Public Lab Wiki documentation

For measuring electrochemically active compounds and microbes in water.

Join the Discussion

on the Public Lab water quality list

Background

Links to other Public Lab Electrochemistry wiki's / research notes

The design, construction, and operation of a low cost, open-source potentiostat (the WheeStat) has been described in a number of Public Lab wikis and research notes. Links to some of these pages are provided here: WheeStat user's manual. A wiki describing how to determine metal ion concentrations electrochemically. A site where you can purchase a WheeStat kit from Public Lab. Instructions for assembling the WheeStat kit. Making / purchasing low cost electrodes.

Potentiostats can be used to test for electrochemically active compounds and microbes in solution, and thus have applications in many areas such as environmental monitoring, food and drug testing. Most commercially-available potentiostats are very expensive ($1000 is on the “cheap” side). There have been several initiatives in the last decade that have focused on designing cheaper alternatives; and when investigating technologies related to water quality assessment. Our aim here is to build on these efforts, and leverage the expertise of the open hardware community in order to build accessible, and capable, devices. Possible applications include:

• Tracking heavy metal concentrations in waterways. Various industrial processes used in the US and abroad can lead to the contamination of water with heavy metals that are dangerous to humans, like mercury and arsenic. An inexpensive, battery-powered potentiostat -- communicating over the cellular network, perhaps, or merely recording locally to an SD card -- might be able to track relative fluctuations in the concentrations of these metals, making monitoring these contaminants easier. Limitations of electrochemical techniques: In order to detect and quantify a chemical species by electrochemical methods, that species has to undergo electron transfer at a voltage that is accessible under the solution conditions being employed. One major limitation to measuring metal species in water is due to oxidation / reductions of water itself. The oxidation of water (to give O2 and H+) limits how positive the voltage can be applied in water. Similarly, reduction to H2 and OH- limits how negative the voltage can be. The voltage limits will depend on things like the choice of electrode used and the pH of the solution. Still, there are a number of metals that can be quantified in water. Mendham, et al, (p 564, referenced below) list the following fifteen specific metals as having been determined by voltammetry:

  • antimony arsenic bismuth cadmium copper gallium
  • germanium gold indium lead mercury silver
  • thallium tin zinc

• A low-cost ‘field lab’ for evaluating water samples. An inexpensive potentiostat, when used according to the proper protocols, might be used to indicate absolute concentrations of heavy metals in water. This could allow citizens and organizations who can’t afford to send water samples to an expensive, bonded laboratory to do their own testing -- particularly relevant in a developing-world context.

• Education. Electrochemistry is an important part of many high school, college, and graduate chemistry curricula; an inexpensive potentiostat could render these curricula more accessible to educational institutions that don’t have the budget for the more expensive commercial versions.

• Research. Making an easily-hackable, programmable, and extensible potentiostat platform, based on a widely-used and well-supported technologies like the Arduino and the Raspberry Pi, could allow for novel electrochemistry applications in the laboratory; when a device that once cost $2000 and didn’t “play nice” with other hardware and software suddenly becomes available for under $200, and can be integrated with easy-to-use, open source software and hardware, researchers will dream up new approaches to open research problems -- and higher-throughput approaches in already-established research areas.

Details

Typically, electrochemical experiments utilize three electrodes, the Working Electrode (WE), Reference Electrode (RE) and Counter Electrode (CE). A research note reviewing some electrodes and describing how to build a set for little cash is provided here. A potentiostat is a three terminal analog feedback control circuit that maintains a pre-determined voltage between the WE and RE by sourcing current from the CE. A rough schematic for a potentiostat is provided below: The CE and WE are made of electrochemically inert conductive materials (we are using graphite, like from pencils, but platinum and gold are popular). The RE is designed to have a well-defined and stable electrochemical potential. By hooking up a power source the energy of electrons in the working electrode can raised and lowered with respect to the reference (and also with respect to compounds in solution). When the energies of electrons in the WE are high enough, they can transfer onto certain chemical species, reducing them. For example, Cu2+ ions can be reduced to Cu+ ions, or to copper metal. Alternatively, when the voltage of the WE is sufficiently positive it can pull electrons off of certain chemicals, oxidizing them. The opposite of the above reactions can be used as an example; Cu+ ion can be oxidized to Cu2+ ion - the voltages (w.r.t. the RE) and currents at which reductions and oxidations happen can be measured, revealing information about the energies and concentrations of the analytes.

The above "Adder Potentiostat" schematic was adapted from chapter 15 of Electrochemical Methods by Bard and Faulkner (reference below).

Work updates

• 8/5/2013: Craig Versek of PVOS has been building off a fully-fledged, open potentiostat design by Jack Summers. Craig is aiming to implement programmable current ranges. In this design, a CMOS analog multiplexer will switch out one of 5 standard current sense resistors (with room for 8 total), which are trimmer rheostats tuned to 250, 2.5k 25.0k 250k and 2.50M Ohms well within 0.5% margin of error.
• 1/8/2014: Smoky Mountain Scientific (Ben Hickman and Jack Summers' lab group) have published research notes describing an open source potentiostat they call the WheeStat. The history of the WheeStat program is described here. The WheeStat software is described here and is available for download here. A description of fabricating the board is provided here and copies of the board can be ordered from OSHPark.com.

Uses

• Assess arsenic, cyanide, other contaminants / toxins in water
• Educational
• Identifying toxins / ingredients in foodstuffs

Development

• olm-pstat - repository for the PLOTS/PVOS Open Lab Monitor potentiostat peripheral

References

• CheapStat
• Cornell U Potentiostat
• [Potentiostat Software on Github](http://bit.ly/15GQcKw
• Gopinath, A. V., and Russell, D., "An Inexpensive Field Portable Programmable Potentiostat", Chem Educator, 2006. pp 23-28.
• Inamdar, S. N., Bhat, M. A., Haram, S. K., "Construction of Ag/AgCl Reference Electrode from Used Felt-Tipped Pen Barrel for Undergraduate Laboratory", J. Chem. Ed., 2009, 86, 355. -Mendham, J., Denney, R. C., Barnes, J. D., Thomas, M. J. K., Vogel's textbook of Quantitative Chemical Analysis, 6th ed., 2000, Prentice Hall, Harlow, England
• Bard, Allen J., and Faulkner, Larry R. Electrochemical Instrumentation. Electrochemical Methods: Fundamentals and Applications, 2nd ed. John Wiley & Sons, Inc., 2001. pp. 632-658
• Nice wikipedia description of what a potentiostat is here.
• A basic description of potentiostat architectures can be found at http://www.consultrsr.com/resources/pstats/design.htm
• Yee, S., Chang, O. K., "A Simple Junction for Reference Electrodes", J. Chem. Ed., 1988, 65, 129
• Thanks to Jack Summers, Benjamin Hickman, Craig Versek, Ian Walls, Jake Wheeler, and Todd Crosby

OHS2013_potentiostat_poster.svg

OHS2013_potentiostat_poster.pdf

For measuring electrochemically active compounds and microbes in water.

Join the Discussion

on the Public Lab Potentiostat list

Background

Links to other Public Lab Electrochemistry wiki's / research notes

The design, construction, and operation of a low cost, open-source potentiostat (the WheeStat) has been described in a number of Public Lab wikis and research notes. Links to some of these pages are provided here: WheeStat user's manual. A wiki describing how to determine metal ion concentrations electrochemically. A site where you can purchase a WheeStat kit from Public Lab. Instructions for assembling the WheeStat kit. Making / purchasing low cost electrodes.

Potentiostats can be used to test for electrochemically active compounds and microbes in solution, and thus have applications in many areas such as environmental monitoring, food and drug testing. Most commercially-available potentiostats are very expensive ($1000 is on the “cheap” side). There have been several initiatives in the last decade that have focused on designing cheaper alternatives; and when investigating technologies related to water quality assessment. Our aim here is to build on these efforts, and leverage the expertise of the open hardware community in order to build accessible, and capable, devices. Possible applications include:

• Tracking heavy metal concentrations in waterways. Various industrial processes used in the US and abroad can lead to the contamination of water with heavy metals that are dangerous to humans, like mercury and arsenic. An inexpensive, battery-powered potentiostat -- communicating over the cellular network, perhaps, or merely recording locally to an SD card -- might be able to track relative fluctuations in the concentrations of these metals, making monitoring these contaminants easier. Limitations of electrochemical techniques: In order to detect and quantify a chemical species by electrochemical methods, that species has to undergo electron transfer at a voltage that is accessible under the solution conditions being employed. One major limitation to measuring metal species in water is due to oxidation / reductions of water itself. The oxidation of water (to give O2 and H+) limits how positive the voltage can be applied in water. Similarly, reduction to H2 and OH- limits how negative the voltage can be. The voltage limits will depend on things like the choice of electrode used and the pH of the solution. Still, there are a number of metals that can be quantified in water. Mendham, et al, (p 564, referenced below) list the following fifteen specific metals as having been determined by voltammetry:

  • antimony arsenic bismuth cadmium copper gallium
  • germanium gold indium lead mercury silver
  • thallium tin zinc

• A low-cost ‘field lab’ for evaluating water samples. An inexpensive potentiostat, when used according to the proper protocols, might be used to indicate absolute concentrations of heavy metals in water. This could allow citizens and organizations who can’t afford to send water samples to an expensive, bonded laboratory to do their own testing -- particularly relevant in a developing-world context.

• Education. Electrochemistry is an important part of many high school, college, and graduate chemistry curricula; an inexpensive potentiostat could render these curricula more accessible to educational institutions that don’t have the budget for the more expensive commercial versions.

• Research. Making an easily-hackable, programmable, and extensible potentiostat platform, based on a widely-used and well-supported technologies like the Arduino and the Raspberry Pi, could allow for novel electrochemistry applications in the laboratory; when a device that once cost $2000 and didn’t “play nice” with other hardware and software suddenly becomes available for under $200, and can be integrated with easy-to-use, open source software and hardware, researchers will dream up new approaches to open research problems -- and higher-throughput approaches in already-established research areas.

Details

Typically, electrochemical experiments utilize three electrodes, the Working Electrode (WE), Reference Electrode (RE) and Counter Electrode (CE). A research note reviewing some electrodes and describing how to build a set for little cash is provided here. A potentiostat is a three terminal analog feedback control circuit that maintains a pre-determined voltage between the WE and RE by sourcing current from the CE. A rough schematic for a potentiostat is provided below: The CE and WE are made of electrochemically inert conductive materials (we are using graphite, like from pencils, but platinum and gold are popular). The RE is designed to have a well-defined and stable electrochemical potential. By hooking up a power source the energy of electrons in the working electrode can raised and lowered with respect to the reference (and also with respect to compounds in solution). When the energies of electrons in the WE are high enough, they can transfer onto certain chemical species, reducing them. For example, Cu2+ ions can be reduced to Cu+ ions, or to copper metal. Alternatively, when the voltage of the WE is sufficiently positive it can pull electrons off of certain chemicals, oxidizing them. The opposite of the above reactions can be used as an example; Cu+ ion can be oxidized to Cu2+ ion - the voltages (w.r.t. the RE) and currents at which reductions and oxidations happen can be measured, revealing information about the energies and concentrations of the analytes.

The above "Adder Potentiostat" schematic was adapted from chapter 15 of Electrochemical Methods by Bard and Faulkner (reference below).

Work updates

• 8/5/2013: Craig Versek of PVOS has been building off a fully-fledged, open potentiostat design by Jack Summers. Craig is aiming to implement programmable current ranges. In this design, a CMOS analog multiplexer will switch out one of 5 standard current sense resistors (with room for 8 total), which are trimmer rheostats tuned to 250, 2.5k 25.0k 250k and 2.50M Ohms well within 0.5% margin of error.
• 1/8/2014: Smoky Mountain Scientific (Ben Hickman and Jack Summers' lab group) have published research notes describing an open source potentiostat they call the WheeStat. The history of the WheeStat program is described here. The WheeStat software is described here and is available for download here. A description of fabricating the board is provided here and copies of the board can be ordered from OSHPark.com.

Uses

• Assess arsenic, cyanide, other contaminants / toxins in water
• Educational
• Identifying toxins / ingredients in foodstuffs

Development

• olm-pstat - repository for the PLOTS/PVOS Open Lab Monitor potentiostat peripheral

References

• CheapStat
• Cornell U Potentiostat
• [Potentiostat Software on Github](http://bit.ly/15GQcKw
• Gopinath, A. V., and Russell, D., "An Inexpensive Field Portable Programmable Potentiostat", Chem Educator, 2006. pp 23-28.
• Inamdar, S. N., Bhat, M. A., Haram, S. K., "Construction of Ag/AgCl Reference Electrode from Used Felt-Tipped Pen Barrel for Undergraduate Laboratory", J. Chem. Ed., 2009, 86, 355. -Mendham, J., Denney, R. C., Barnes, J. D., Thomas, M. J. K., Vogel's textbook of Quantitative Chemical Analysis, 6th ed., 2000, Prentice Hall, Harlow, England
• Bard, Allen J., and Faulkner, Larry R. Electrochemical Instrumentation. Electrochemical Methods: Fundamentals and Applications, 2nd ed. John Wiley & Sons, Inc., 2001. pp. 632-658
• Nice wikipedia description of what a potentiostat is here.
• A basic description of potentiostat architectures can be found at http://www.consultrsr.com/resources/pstats/design.htm
• Yee, S., Chang, O. K., "A Simple Junction for Reference Electrodes", J. Chem. Ed., 1988, 65, 129
• Thanks to Jack Summers, Benjamin Hickman, Craig Versek, Ian Walls, Jake Wheeler, and Todd Crosby

OHS2013_potentiostat_poster.svg

OHS2013_potentiostat_poster.pdf

Join the Discussion

on the Public Lab Potentiostat list

Background

Links to other Public Lab Electrochemistry wiki's / research notes The design, construction, and operation of a low cost, open-source potentiostat (the WheeStat) has been described in a number of Public Lab wikis and research notes. Links to some of these pages are provided here: WheeStat user's manual. A wiki describing how to determine metal ion concentrations electrochemically. A site where you can purchase a WheeStat kit from Public Lab. Instructions for assembling the WheeStat kit. Making / purchasing low cost electrodes.

Potentiostats can be used to test for electrochemically active compounds and microbes in solution, and thus have applications in many areas such as environmental monitoring, food and drug testing. Most commercially-available potentiostats are very expensive ($1000 is on the “cheap” side). There have been several initiatives in the last decade that have focused on designing cheaper alternatives; and when investigating technologies related to water quality assessment. Our aim here is to build on these efforts, and leverage the expertise of the open hardware community in order to build accessible, and capable, devices. Possible applications include:

• Tracking heavy metal concentrations in waterways. Various industrial processes used in the US and abroad can lead to the contamination of water with heavy metals that are dangerous to humans, like mercury and arsenic. An inexpensive, battery-powered potentiostat -- communicating over the cellular network, perhaps, or merely recording locally to an SD card -- might be able to track relative fluctuations in the concentrations of these metals, making monitoring these contaminants easier. Limitations of electrochemical techniques: In order to detect and quantify a chemical species by electrochemical methods, that species has to undergo electron transfer at a voltage that is accessible under the solution conditions being employed. One major limitation to measuring metal species in water is due to oxidation / reductions of water itself. The oxidation of water (to give O2 and H+) limits how positive the voltage can be applied in water. Similarly, reduction to H2 and OH- limits how negative the voltage can be. The voltage limits will depend on things like the choice of electrode used and the pH of the solution. Still, there are a number of metals that can be quantified in water. Mendham, et al, (p 564, referenced below) list the following fifteen specific metals as having been determined by voltammetry:

  • antimony arsenic bismuth cadmium copper gallium
  • germanium gold indium lead mercury silver
  • thallium tin zinc

• A low-cost ‘field lab’ for evaluating water samples. An inexpensive potentiostat, when used according to the proper protocols, might be used to indicate absolute concentrations of heavy metals in water. This could allow citizens and organizations who can’t afford to send water samples to an expensive, bonded laboratory to do their own testing -- particularly relevant in a developing-world context.

• Education. Electrochemistry is an important part of many high school, college, and graduate chemistry curricula; an inexpensive potentiostat could render these curricula more accessible to educational institutions that don’t have the budget for the more expensive commercial versions.

• Research. Making an easily-hackable, programmable, and extensible potentiostat platform, based on a widely-used and well-supported technologies like the Arduino and the Raspberry Pi, could allow for novel electrochemistry applications in the laboratory; when a device that once cost $2000 and didn’t “play nice” with other hardware and software suddenly becomes available for under $200, and can be integrated with easy-to-use, open source software and hardware, researchers will dream up new approaches to open research problems -- and higher-throughput approaches in already-established research areas.

Details

Typically, electrochemical experiments utilize three electrodes, the Working Electrode (WE), Reference Electrode (RE) and Counter Electrode (CE). A research note reviewing some electrodes and describing how to build a set for little cash is provided here. A potentiostat is a three terminal analog feedback control circuit that maintains a pre-determined voltage between the WE and RE by sourcing current from the CE. A rough schematic for a potentiostat is provided below: The CE and WE are made of electrochemically inert conductive materials (we are using graphite, like from pencils, but platinum and gold are popular). The RE is designed to have a well-defined and stable electrochemical potential. By hooking up a power source the energy of electrons in the working electrode can raised and lowered with respect to the reference (and also with respect to compounds in solution). When the energies of electrons in the WE are high enough, they can transfer onto certain chemical species, reducing them. For example, Cu2+ ions can be reduced to Cu+ ions, or to copper metal. Alternatively, when the voltage of the WE is sufficiently positive it can pull electrons off of certain chemicals, oxidizing them. The opposite of the above reactions can be used as an example; Cu+ ion can be oxidized to Cu2+ ion - the voltages (w.r.t. the RE) and currents at which reductions and oxidations happen can be measured, revealing information about the energies and concentrations of the analytes.

The above "Adder Potentiostat" schematic was adapted from chapter 15 of Electrochemical Methods by Bard and Faulkner (reference below).

Work updates

• 8/5/2013: Craig Versek of PVOS has been building off a fully-fledged, open potentiostat design by Jack Summers. Craig is aiming to implement programmable current ranges. In this design, a CMOS analog multiplexer will switch out one of 5 standard current sense resistors (with room for 8 total), which are trimmer rheostats tuned to 250, 2.5k 25.0k 250k and 2.50M Ohms well within 0.5% margin of error.
• 1/8/2014: Smoky Mountain Scientific (Ben Hickman and Jack Summers' lab group) have published research notes describing an open source potentiostat they call the WheeStat. The history of the WheeStat program is described here. The WheeStat software is described here and is available for download here. A description of fabricating the board is provided here and copies of the board can be ordered from OSHPark.com.

Uses

• Assess arsenic, cyanide, other contaminants / toxins in water
• Educational
• Identifying toxins / ingredients in foodstuffs

Development

• olm-pstat - repository for the PLOTS/PVOS Open Lab Monitor potentiostat peripheral

References

• CheapStat
• Cornell U Potentiostat
• [Potentiostat Software on Github](http://bit.ly/15GQcKw
• Gopinath, A. V., and Russell, D., "An Inexpensive Field Portable Programmable Potentiostat", Chem Educator, 2006. pp 23-28.
• Inamdar, S. N., Bhat, M. A., Haram, S. K., "Construction of Ag/AgCl Reference Electrode from Used Felt-Tipped Pen Barrel for Undergraduate Laboratory", J. Chem. Ed., 2009, 86, 355. -Mendham, J., Denney, R. C., Barnes, J. D., Thomas, M. J. K., Vogel's textbook of Quantitative Chemical Analysis, 6th ed., 2000, Prentice Hall, Harlow, England
• Bard, Allen J., and Faulkner, Larry R. Electrochemical Instrumentation. Electrochemical Methods: Fundamentals and Applications, 2nd ed. John Wiley & Sons, Inc., 2001. pp. 632-658
• Nice wikipedia description of what a potentiostat is here.
• A basic description of potentiostat architectures can be found at http://www.consultrsr.com/resources/pstats/design.htm
• Yee, S., Chang, O. K., "A Simple Junction for Reference Electrodes", J. Chem. Ed., 1988, 65, 129
• Thanks to Jack Summers, Benjamin Hickman, Craig Versek, Ian Walls, Jake Wheeler, and Todd Crosby

OHS2013_potentiostat_poster.svg

OHS2013_potentiostat_poster.pdf

Join the Discussion

on the Public Lab Potentiostat list

Background

Links to other Public Lab Electrochemistry wiki's / research notes The design, construction, and operation of a low cost, open-source potentiostat (the WheeStat) has been described in a number of Public Lab wikis and research notes. Links to some of these pages are provided below. WheeStat user's manual Determining metal ion concentrations electrochemically. Purchase a WheeStat kit WheeStat kit assembly instructions Making / purchasing low cost electrodes

Potentiostats can be used to test for electrochemically active compounds and microbes in solution, and thus have applications in many areas such as environmental monitoring, food and drug testing. Most commercially-available potentiostats are very expensive ($1000 is on the “cheap” side). There have been several initiatives in the last decade that have focused on designing cheaper alternatives; and when investigating technologies related to water quality assessment. Our aim here is to build on these efforts, and leverage the expertise of the open hardware community in order to build accessible, and capable, devices. Possible applications include:

• Tracking heavy metal concentrations in waterways. Various industrial processes used in the US and abroad can lead to the contamination of water with heavy metals that are dangerous to humans, like mercury and arsenic. An inexpensive, battery-powered potentiostat -- communicating over the cellular network, perhaps, or merely recording locally to an SD card -- might be able to track relative fluctuations in the concentrations of these metals, making monitoring these contaminants easier. Limitations of electrochemical techniques: In order to detect and quantify a chemical species by electrochemical methods, that species has to undergo electron transfer at a voltage that is accessible under the solution conditions being employed. One major limitation to measuring metal species in water is due to oxidation / reductions of water itself. The oxidation of water (to give O2 and H+) limits how positive the voltage can be applied in water. Similarly, reduction to H2 and OH- limits how negative the voltage can be. The voltage limits will depend on things like the choice of electrode used and the pH of the solution. Still, there are a number of metals that can be quantified in water. Mendham, et al, (p 564, referenced below) list the following fifteen specific metals as having been determined by voltammetry:

  • antimony arsenic bismuth cadmium copper gallium
  • germanium gold indium lead mercury silver
  • thallium tin zinc

• A low-cost ‘field lab’ for evaluating water samples. An inexpensive potentiostat, when used according to the proper protocols, might be used to indicate absolute concentrations of heavy metals in water. This could allow citizens and organizations who can’t afford to send water samples to an expensive, bonded laboratory to do their own testing -- particularly relevant in a developing-world context.

• Education. Electrochemistry is an important part of many high school, college, and graduate chemistry curricula; an inexpensive potentiostat could render these curricula more accessible to educational institutions that don’t have the budget for the more expensive commercial versions.

• Research. Making an easily-hackable, programmable, and extensible potentiostat platform, based on a widely-used and well-supported technologies like the Arduino and the Raspberry Pi, could allow for novel electrochemistry applications in the laboratory; when a device that once cost $2000 and didn’t “play nice” with other hardware and software suddenly becomes available for under $200, and can be integrated with easy-to-use, open source software and hardware, researchers will dream up new approaches to open research problems -- and higher-throughput approaches in already-established research areas.

Details

Typically, electrochemical experiments utilize three electrodes, the Working Electrode (WE), Reference Electrode (RE) and Counter Electrode (CE). A research note reviewing some electrodes and describing how to build a set for little cash is provided here. A potentiostat is a three terminal analog feedback control circuit that maintains a pre-determined voltage between the WE and RE by sourcing current from the CE. A rough schematic for a potentiostat is provided below: The CE and WE are made of electrochemically inert conductive materials (we are using graphite, like from pencils, but platinum and gold are popular). The RE is designed to have a well-defined and stable electrochemical potential. By hooking up a power source the energy of electrons in the working electrode can raised and lowered with respect to the reference (and also with respect to compounds in solution). When the energies of electrons in the WE are high enough, they can transfer onto certain chemical species, reducing them. For example, Cu2+ ions can be reduced to Cu+ ions, or to copper metal. Alternatively, when the voltage of the WE is sufficiently positive it can pull electrons off of certain chemicals, oxidizing them. The opposite of the above reactions can be used as an example; Cu+ ion can be oxidized to Cu2+ ion - the voltages (w.r.t. the RE) and currents at which reductions and oxidations happen can be measured, revealing information about the energies and concentrations of the analytes.

The above "Adder Potentiostat" schematic was adapted from chapter 15 of Electrochemical Methods by Bard and Faulkner (reference below).

Work updates

• 8/5/2013: Craig Versek of PVOS has been building off a fully-fledged, open potentiostat design by Jack Summers. Craig is aiming to implement programmable current ranges. In this design, a CMOS analog multiplexer will switch out one of 5 standard current sense resistors (with room for 8 total), which are trimmer rheostats tuned to 250, 2.5k 25.0k 250k and 2.50M Ohms well within 0.5% margin of error.
• 1/8/2014: Smoky Mountain Scientific (Ben Hickman and Jack Summers' lab group) have published research notes describing an open source potentiostat they call the WheeStat. The history of the WheeStat program is described here. The WheeStat software is described here and is available for download here. A description of fabricating the board is provided here and copies of the board can be ordered from OSHPark.com.

Uses

• Assess arsenic, cyanide, other contaminants / toxins in water
• Educational
• Identifying toxins / ingredients in foodstuffs

Development

• olm-pstat - repository for the PLOTS/PVOS Open Lab Monitor potentiostat peripheral

References

• CheapStat
• Cornell U Potentiostat
• [Potentiostat Software on Github](http://bit.ly/15GQcKw
• Gopinath, A. V., and Russell, D., "An Inexpensive Field Portable Programmable Potentiostat", Chem Educator, 2006. pp 23-28.
• Inamdar, S. N., Bhat, M. A., Haram, S. K., "Construction of Ag/AgCl Reference Electrode from Used Felt-Tipped Pen Barrel for Undergraduate Laboratory", J. Chem. Ed., 2009, 86, 355. -Mendham, J., Denney, R. C., Barnes, J. D., Thomas, M. J. K., Vogel's textbook of Quantitative Chemical Analysis, 6th ed., 2000, Prentice Hall, Harlow, England
• Bard, Allen J., and Faulkner, Larry R. Electrochemical Instrumentation. Electrochemical Methods: Fundamentals and Applications, 2nd ed. John Wiley & Sons, Inc., 2001. pp. 632-658
• Nice wikipedia description of what a potentiostat is here.
• A basic description of potentiostat architectures can be found at http://www.consultrsr.com/resources/pstats/design.htm
• Yee, S., Chang, O. K., "A Simple Junction for Reference Electrodes", J. Chem. Ed., 1988, 65, 129
• Thanks to Jack Summers, Benjamin Hickman, Craig Versek, Ian Walls, Jake Wheeler, and Todd Crosby

OHS2013_potentiostat_poster.svg

OHS2013_potentiostat_poster.pdf

Join the Discussion

on the Public Lab Potentiostat list

Background

Potentiostats can be used to test for electrochemically active compounds and microbes in solution, and thus have applications in many areas such as environmental monitoring, food and drug testing. Most commercially-available potentiostats are very expensive ($1000 is on the “cheap” side). There have been several initiatives in the last decade that have focused on designing cheaper alternatives; and when investigating technologies related to water quality assessment. Our aim here is to build on these efforts, and leverage the expertise of the open hardware community in order to build accessible, and capable, devices. Possible applications include:

• Tracking heavy metal concentrations in waterways. Various industrial processes used in the US and abroad can lead to the contamination of water with heavy metals that are dangerous to humans, like mercury and arsenic. An inexpensive, battery-powered potentiostat -- communicating over the cellular network, perhaps, or merely recording locally to an SD card -- might be able to track relative fluctuations in the concentrations of these metals, making monitoring these contaminants easier. Limitations of electrochemical techniques: In order to detect and quantify a chemical species by electrochemical methods, that species has to undergo electron transfer at a voltage that is accessible under the solution conditions being employed. One major limitation to measuring metal species in water is due to oxidation / reductions of water itself. The oxidation of water (to give O2 and H+) limits how positive the voltage can be applied in water. Similarly, reduction to H2 and OH- limits how negative the voltage can be. The voltage limits will depend on things like the choice of electrode used and the pH of the solution. Still, there are a number of metals that can be quantified in water. Mendham, et al, (p 564, referenced below) list the following fifteen specific metals as having been determined by voltammetry:

  • antimony arsenic bismuth cadmium copper gallium
  • germanium gold indium lead mercury silver
  • thallium tin zinc

• A low-cost ‘field lab’ for evaluating water samples. An inexpensive potentiostat, when used according to the proper protocols, might be used to indicate absolute concentrations of heavy metals in water. This could allow citizens and organizations who can’t afford to send water samples to an expensive, bonded laboratory to do their own testing -- particularly relevant in a developing-world context.

• Education. Electrochemistry is an important part of many high school, college, and graduate chemistry curricula; an inexpensive potentiostat could render these curricula more accessible to educational institutions that don’t have the budget for the more expensive commercial versions.

• Research. Making an easily-hackable, programmable, and extensible potentiostat platform, based on a widely-used and well-supported technologies like the Arduino and the Raspberry Pi, could allow for novel electrochemistry applications in the laboratory; when a device that once cost $2000 and didn’t “play nice” with other hardware and software suddenly becomes available for under $200, and can be integrated with easy-to-use, open source software and hardware, researchers will dream up new approaches to open research problems -- and higher-throughput approaches in already-established research areas.

Details

Typically, electrochemical experiments utilize three electrodes, the Working Electrode (WE), Reference Electrode (RE) and Counter Electrode (CE). A research note reviewing some electrodes and describing how to build a set for little cash is provided here. A potentiostat is a three terminal analog feedback control circuit that maintains a pre-determined voltage between the WE and RE by sourcing current from the CE. A rough schematic for a potentiostat is provided below: The CE and WE are made of electrochemically inert conductive materials (we are using graphite, like from pencils, but platinum and gold are popular). The RE is designed to have a well-defined and stable electrochemical potential. By hooking up a power source the energy of electrons in the working electrode can raised and lowered with respect to the reference (and also with respect to compounds in solution). When the energies of electrons in the WE are high enough, they can transfer onto certain chemical species, reducing them. For example, Cu2+ ions can be reduced to Cu+ ions, or to copper metal. Alternatively, when the voltage of the WE is sufficiently positive it can pull electrons off of certain chemicals, oxidizing them. The opposite of the above reactions can be used as an example; Cu+ ion can be oxidized to Cu2+ ion - the voltages (w.r.t. the RE) and currents at which reductions and oxidations happen can be measured, revealing information about the energies and concentrations of the analytes.

The above "Adder Potentiostat" schematic was adapted from chapter 15 of Electrochemical Methods by Bard and Faulkner (reference below).

Work updates

• 8/5/2013: Craig Versek of PVOS has been building off a fully-fledged, open potentiostat design by Jack Summers. Craig is aiming to implement programmable current ranges. In this design, a CMOS analog multiplexer will switch out one of 5 standard current sense resistors (with room for 8 total), which are trimmer rheostats tuned to 250, 2.5k 25.0k 250k and 2.50M Ohms well within 0.5% margin of error.
• 1/8/2014: Smoky Mountain Scientific (Ben Hickman and Jack Summers' lab group) have published research notes describing an open source potentiostat they call the WheeStat. The history of the WheeStat program is described here. The WheeStat software is described here and is available for download here. A description of fabricating the board is provided here and copies of the board can be ordered from OSHPark.com.

Uses

• Assess arsenic, cyanide, other contaminants / toxins in water
• Educational
• Identifying toxins / ingredients in foodstuffs

Development

• olm-pstat - repository for the PLOTS/PVOS Open Lab Monitor potentiostat peripheral

References

• CheapStat
• Cornell U Potentiostat
• [Potentiostat Software on Github](http://bit.ly/15GQcKw
• Gopinath, A. V., and Russell, D., "An Inexpensive Field Portable Programmable Potentiostat", Chem Educator, 2006. pp 23-28.
• Inamdar, S. N., Bhat, M. A., Haram, S. K., "Construction of Ag/AgCl Reference Electrode from Used Felt-Tipped Pen Barrel for Undergraduate Laboratory", J. Chem. Ed., 2009, 86, 355. -Mendham, J., Denney, R. C., Barnes, J. D., Thomas, M. J. K., Vogel's textbook of Quantitative Chemical Analysis, 6th ed., 2000, Prentice Hall, Harlow, England
• Bard, Allen J., and Faulkner, Larry R. Electrochemical Instrumentation. Electrochemical Methods: Fundamentals and Applications, 2nd ed. John Wiley & Sons, Inc., 2001. pp. 632-658
• Nice wikipedia description of what a potentiostat is here.
• A basic description of potentiostat architectures can be found at http://www.consultrsr.com/resources/pstats/design.htm
• Yee, S., Chang, O. K., "A Simple Junction for Reference Electrodes", J. Chem. Ed., 1988, 65, 129
• Thanks to Jack Summers, Benjamin Hickman, Craig Versek, Ian Walls, Jake Wheeler, and Todd Crosby

OHS2013_potentiostat_poster.svg

OHS2013_potentiostat_poster.pdf

Join the Discussion

on the Public Lab Potentiostat list

Background

Potentiostats can be used to test for electrochemically active compounds and microbes in solution, and thus have applications in many areas such as environmental monitoring, food and drug testing. Most commercially-available potentiostats are very expensive ($1000 is on the “cheap” side). There have been several initiatives in the last decade that have focused on designing cheaper alternatives; and when investigating technologies related to water quality assessment. Our aim here is to build on these efforts, and leverage the expertise of the open hardware community in order to build accessible, and capable, devices. Possible applications include:

• Tracking heavy metal concentrations in waterways. Various industrial processes used in the US and abroad can lead to the contamination of water with heavy metals that are dangerous to humans, like mercury and arsenic. An inexpensive, battery-powered potentiostat -- communicating over the cellular network, perhaps, or merely recording locally to an SD card -- might be able to track relative fluctuations in the concentrations of these metals, making monitoring these contaminants easier. Limitations of electrochemical techniques: In order to detect and quantify a chemical species by electrochemical methods, that species has to undergo electron transfer at a voltage that is accessible under the solution conditions being employed. One major limitation to measuring metal species in water is due to oxidation / reductions of water itself. The oxidation of water (to give O2 and H+) limits how positive the voltage can be applied in water. Similarly, reduction to H2 and OH- limits how negative the voltage can be. The voltage limits will depend on things like the choice of electrode used and the pH of the solution. Still, there are a number of metals that can be quantified in water. Mendham, et al, (p 564, referenced below) list the following fifteen specific metals as having been determined by voltammetry:

  • antimony arsenic bismuth cadmium copper gallium
  • germanium gold indium lead mercury silver
  • thallium tin zinc

• A low-cost ‘field lab’ for evaluating water samples. An inexpensive potentiostat, when used according to the proper protocols, might be used to indicate absolute concentrations of heavy metals in water. This could allow citizens and organizations who can’t afford to send water samples to an expensive, bonded laboratory to do their own testing -- particularly relevant in a developing-world context.

• Education. Electrochemistry is an important part of many high school, college, and graduate chemistry curricula; an inexpensive potentiostat could render these curricula more accessible to educational institutions that don’t have the budget for the more expensive commercial versions.

• Research. Making an easily-hackable, programmable, and extensible potentiostat platform, based on a widely-used and well-supported technologies like the Arduino and the Raspberry Pi, could allow for novel electrochemistry applications in the laboratory; when a device that once cost $2000 and didn’t “play nice” with other hardware and software suddenly becomes available for under $200, and can be integrated with easy-to-use, open source software and hardware, researchers will dream up new approaches to open research problems -- and higher-throughput approaches in already-established research areas.

Details

Typically, electrochemical experiments utilize three electrodes, the Working Electrode (WE), Reference Electrode (RE) and Counter Electrode (CE). A potentiostat is a three terminal analog feedback control circuit that maintains a pre-determined voltage between the WE and RE by sourcing current from the CE. A rough schematic for a potentiostat is provided below: The CE and WE are made of electrochemically inert conductive materials (we are using graphite, like from pencils, but platinum and gold are popular). The RE is designed to have a well-defined and stable electrochemical potential. No current passes through the RE. An inexpensive RE can be made from a piece of silver wire coated with silver chloride. The silver is oxidized while immersed in a chloride salt solution. This can be done by dipping the wire in bleach (need ref) or by holding the wire at a sufficiently positive (oxidizing) voltage. The Ag (metal) / AgCl (sparingly water soluble salt) couple electrode is sequestered in a glass tube with a saturated potassium chloride solution, which is fitted with a porous separator to allow ion exchange with the cell. By hooking up a power source the energy of electrons in the working electrode can raised and lowered with respect to the reference (and also with respect to compounds in solution). When the energies of electrons in the WE are high enough, they can transfer onto certain chemical species, reducing them. For example, Cu2+ ions can be reduced to Cu+ ions, or to copper metal. Alternatively, when the voltage of the WE is sufficiently positive it can pull electrons off of certain chemicals, oxidizing them. The opposite of the above reactions can be used as an example; Cu+ ion can be oxidized to Cu2+ ion - the voltages (w.r.t. the RE) and currents at which reductions and oxidations happen can be measured, revealing information about the energies and concentrations of the analytes.

The above "Adder Potentiostat" schematic was adapted from chapter 15 of Electrochemical Methods by Bard and Faulkner (reference below).

Work updates

• 8/5/2013: Craig Versek of PVOS has been building off a fully-fledged, open potentiostat design by Jack Summers. Craig is aiming to implement programmable current ranges. In this design, a CMOS analog multiplexer will switch out one of 5 standard current sense resistors (with room for 8 total), which are trimmer rheostats tuned to 250, 2.5k 25.0k 250k and 2.50M Ohms well within 0.5% margin of error.
• 1/8/2014: Smoky Mountain Scientific (Ben Hickman and Jack Summers' lab group) have published research notes describing an open source potentiostat they call the WheeStat. The history of the WheeStat program is described here. The WheeStat software is described here and is available for download here. A description of fabricating the board is provided here and copies of the board can be ordered from OSHPark.com.

Uses

• Assess arsenic, cyanide, other contaminants / toxins in water
• Educational
• Identifying toxins / ingredients in foodstuffs

Development

• olm-pstat - repository for the PLOTS/PVOS Open Lab Monitor potentiostat peripheral

References

• CheapStat
• Cornell U Potentiostat
• [Potentiostat Software on Github](http://bit.ly/15GQcKw
• Gopinath, A. V., and Russell, D., "An Inexpensive Field Portable Programmable Potentiostat", Chem Educator, 2006. pp 23-28.
• Inamdar, S. N., Bhat, M. A., Haram, S. K., "Construction of Ag/AgCl Reference Electrode from Used Felt-Tipped Pen Barrel for Undergraduate Laboratory", J. Chem. Ed., 2009, 86, 355. -Mendham, J., Denney, R. C., Barnes, J. D., Thomas, M. J. K., Vogel's textbook of Quantitative Chemical Analysis, 6th ed., 2000, Prentice Hall, Harlow, England
• Bard, Allen J., and Faulkner, Larry R. Electrochemical Instrumentation. Electrochemical Methods: Fundamentals and Applications, 2nd ed. John Wiley & Sons, Inc., 2001. pp. 632-658
• Nice wikipedia description of what a potentiostat is here.
• A basic description of potentiostat architectures can be found at http://www.consultrsr.com/resources/pstats/design.htm
• Yee, S., Chang, O. K., "A Simple Junction for Reference Electrodes", J. Chem. Ed., 1988, 65, 129
• Thanks to Jack Summers, Benjamin Hickman, Craig Versek, Ian Walls, Jake Wheeler, and Todd Crosby

OHS2013_potentiostat_poster.svg

OHS2013_potentiostat_poster.pdf

Join the Discussion

on the Public Lab Potentiostat list

Background

Potentiostats can be used to test for electrochemically active compounds and microbes in solution, and thus have applications in many areas such as environmental monitoring, food and drug testing. Most commercially-available potentiostats are very expensive ($1000 is on the “cheap” side). There have been several initiatives in the last decade that have focused on designing cheaper alternatives; and when investigating technologies related to water quality assessment. Our aim here is to build on these efforts, and leverage the expertise of the open hardware community in order to build accessible, and capable, devices. Possible applications include:

• Tracking heavy metal concentrations in waterways. Various industrial processes used in the US and abroad can lead to the contamination of water with heavy metals that are dangerous to humans, like mercury and arsenic. An inexpensive, battery-powered potentiostat -- communicating over the cellular network, perhaps, or merely recording locally to an SD card -- might be able to track relative fluctuations in the concentrations of these metals, making monitoring these contaminants easier.

• A low-cost ‘field lab’ for evaluating water samples. An inexpensive potentiostat, when used according to the proper protocols, might be used to indicate absolute concentrations of heavy metals in water. This could allow citizens and organizations who can’t afford to send water samples to an expensive, bonded laboratory to do their own testing -- particularly relevant in a developing-world context.

• Education. Electrochemistry is an important part of many high school, college, and graduate chemistry curricula; an inexpensive potentiostat could render these curricula more accessible to educational institutions that don’t have the budget for the more expensive commercial versions.

• Research. Making an easily-hackable, programmable, and extensible potentiostat platform, based on a widely-used and well-supported technologies like the Arduino and the Raspberry Pi, could allow for novel electrochemistry applications in the laboratory; when a device that once cost $2000 and didn’t “play nice” with other hardware and software suddenly becomes available for under $200, and can be integrated with easy-to-use, open source software and hardware, researchers will dream up new approaches to open research problems -- and higher-throughput approaches in already-established research areas.

Details

Typically, electrochemical experiments utilize three electrodes, the Working Electrode (WE), Reference Electrode (RE) and Counter Electrode (CE). A potentiostat is a three terminal analog feedback control circuit that maintains a pre-determined voltage between the WE and RE by sourcing current from the CE. A rough schematic for a potentiostat is provided below: The CE and WE are made of electrochemically inert conductive materials (we are using graphite, like from pencils, but platinum and gold are popular). The RE is designed to have a well-defined and stable electrochemical potential. No current passes through the RE. An inexpensive RE can be made from a piece of silver wire coated with silver chloride. The silver is oxidized while immersed in a chloride salt solution. This can be done by dipping the wire in bleach (need ref) or by holding the wire at a sufficiently positive (oxidizing) voltage. The Ag (metal) / AgCl (sparingly water soluble salt) couple electrode is sequestered in a glass tube with a saturated potassium chloride solution, which is fitted with a porous separator to allow ion exchange with the cell. By hooking up a power source the energy of electrons in the working electrode can raised and lowered with respect to the reference (and also with respect to compounds in solution). When the energies of electrons in the WE are high enough, they can transfer onto certain chemical species, reducing them. For example, Cu2+ ions can be reduced to Cu+ ions, or to copper metal. Alternatively, when the voltage of the WE is sufficiently positive it can pull electrons off of certain chemicals, oxidizing them. The opposite of the above reactions can be used as an example; Cu+ ion can be oxidized to Cu2+ ion - the voltages (w.r.t. the RE) and currents at which reductions and oxidations happen can be measured, revealing information about the energies and concentrations of the analytes.

The above "Adder Potentiostat" schematic was adapted from chapter 15 of Electrochemical Methods by Bard and Faulkner (reference below).

Work updates

• 8/5/2013: Craig Versek of PVOS has been building off a fully-fledged, open potentiostat design by Jack Summers. Craig is aiming to implement programmable current ranges. In this design, a CMOS analog multiplexer will switch out one of 5 standard current sense resistors (with room for 8 total), which are trimmer rheostats tuned to 250, 2.5k 25.0k 250k and 2.50M Ohms well within 0.5% margin of error. -1/8/2014: Smoky Mountain Scientific (Ben Hickman and Jack Summers' lab group) have published research notes describing an open source potentiostat they call the WheeStat. The history of the WheeStat program is described here. The WheeStat software is described here and is available for download here. A description of fabricating the board is provided here and copies of the board can be ordered from OSHPark.com.

Uses

• Assess arsenic, cyanide, other contaminants / toxins in water
• Mendham, et al, (p 564, reference below) list the following specific metals that can be determined by voltammetry:
  • antimony arsenic bismuth cadmium copper gallium
  • germanium gold indium lead mercury silver
  • thallium tin zinc
• Educational
• Identifying toxins / ingredients in foodstuffs

Development

• olm-pstat - repository for the PLOTS/PVOS Open Lab Monitor potentiostat peripheral

References

• CheapStat
• Cornell U Potentiostat
• [Potentiostat Software on Github](http://bit.ly/15GQcKw
• A.V.Gopinath and D. Russell, "An Inexpensive Field Portable Programmable Potentiostat", Chem Educator, 2006. pp 23-28. -Mendham, J., Denney, R. C., Barnes, J. D., Thomas, M. J. K., Vogel's textbook of Quantitative Chemical Analysis, 6th ed., 2000, Prentice Hall, Harlow, England
• Bard, Allen J., and Faulkner, Larry R. Electrochemical Instrumentation. Electrochemical Methods: Fundamentals and Applications, 2nd ed. John Wiley & Sons, Inc., 2001. pp. 632-658
• Nice wikipedia description of what a potentiostat is here.
• A basic description of potentiostat architectures can be found at http://www.consultrsr.com/resources/pstats/design.htm
• Thanks to Jack Summers, Benjamin Hickman, Craig Versek, Ian Walls, Jake Wheeler, and Todd Crosby

OHS2013_potentiostat_poster.svg

OHS2013_potentiostat_poster.pdf

Join the Discussion

on the Public Lab Potentiostat list

Background

Potentiostats can be used to test for electrochemically active compounds and microbes in solution, and thus have applications in many areas such as environmental monitoring, food and drug testing. Most commercially-available potentiostats are very expensive ($1000 is on the “cheap” side). There have been several initiatives in the last decade that have focused on designing cheaper alternatives; and when investigating technologies related to water quality assessment. Our aim here is to build on these efforts, and leverage the expertise of the open hardware community in order to build accessible, and capable, devices. Possible applications include:

• Tracking heavy metal concentrations in waterways. Various industrial processes used in the US and abroad can lead to the contamination of water with heavy metals that are dangerous to humans, like mercury and arsenic. An inexpensive, battery-powered potentiostat -- communicating over the cellular network, perhaps, or merely recording locally to an SD card -- might be able to track relative fluctuations in the concentrations of these metals, making monitoring these contaminants easier.

• A low-cost ‘field lab’ for evaluating water samples. An inexpensive potentiostat, when used according to the proper protocols, might be used to indicate absolute concentrations of heavy metals in water. This could allow citizens and organizations who can’t afford to send water samples to an expensive, bonded laboratory to do their own testing -- particularly relevant in a developing-world context.

• Education. Electrochemistry is an important part of many high school, college, and graduate chemistry curricula; an inexpensive potentiostat could render these curricula more accessible to educational institutions that don’t have the budget for the more expensive commercial versions.

• Research. Making an easily-hackable, programmable, and extensible potentiostat platform, based on a widely-used and well-supported technologies like the Arduino and the Raspberry Pi, could allow for novel electrochemistry applications in the laboratory; when a device that once cost $2000 and didn’t “play nice” with other hardware and software suddenly becomes available for under $200, and can be integrated with easy-to-use, open source software and hardware, researchers will dream up new approaches to open research problems -- and higher-throughput approaches in already-established research areas.

Details

Typically, electrochemical experiments utilize three electrodes, the Working Electrode (WE), Reference Electrode (RE) and Counter Electrode (CE). A potentiostat is a three terminal analog feedback control circuit that maintains a pre-determined voltage between the WE and RE by sourcing current from the CE. A rough schematic for a potentiostat is provided below: The CE and WE are made of electrochemically inert conductive materials (we are using graphite, like from pencils, but platinum and gold are popular). The RE is designed to have a well-defined and stable electrochemical potential. No current passes through the RE. An inexpensive RE can be made from a piece of silver wire coated with silver chloride. The silver is oxidized while immersed in a chloride salt solution. This can be done by dipping the wire in bleach (need ref) or by holding the wire at a sufficiently positive (oxidizing) voltage. The Ag (metal) / AgCl (sparingly water soluble salt) couple electrode is sequestered in a glass tube with a saturated potassium chloride solution, which is fitted with a porous separator to allow ion exchange with the cell. By hooking up a power source the energy of electrons in the working electrode can raised and lowered with respect to the reference (and also with respect to compounds in solution). When the energies of electrons in the WE are high enough, they can transfer onto certain chemical species, reducing them. For example, Cu2+ ions can be reduced to Cu+ ions, or to copper metal. Alternatively, when the voltage of the WE is sufficiently positive it can pull electrons off of certain chemicals, oxidizing them. The opposite of the above reactions can be used as an example; Cu+ ion can be oxidized to Cu2+ ion - the voltages (w.r.t. the RE) and currents at which reductions and oxidations happen can be measured, revealing information about the energies and concentrations of the analytes.

Reference for the above "Adder Potentiostat" circuit: Bard, Allen J., and Faulkner, Larry R. Chap. 15: Electrochemical Instrumentation. Electrochemical Methods: Fundamentals and Applications, 2nd ed. John Wiley & Sons, Inc., 2001. pp. 632-658

Work updates

• 8/5/2013: Craig Versek of PVOS has been building off a fully-fledged, open potentiostat design by Jack Summers. Craig is aiming to implement programmable current ranges. In this design, a CMOS analog multiplexer will switch out one of 5 standard current sense resistors (with room for 8 total), which are trimmer rheostats tuned to 250, 2.5k 25.0k 250k and 2.50M Ohms well within 0.5% margin of error. 1/8/2014: Smoky Mountain Scientific (Ben Hickman and Jack Summers' lab group) have published research notes describing an open source potentiostat they call the WheeStat. The history of the WheeStat program is described here. The WheeStat software is described here and is available for download here. A description of fabricating the board is provided here and copies of the board can be ordered from OSHPark.com.

References

• CheapStat
• Cornell U Potentiostat
• [Potentiostat Software on Github](http://bit.ly/15GQcKw

• A.V.Gopinath and D. Russell, "An Inexpensive Field Portable Programmable Potentiostat", Chem Educator, 2006. pp 23-28.

• Nice wikipedia description of what a potentiostat is here.

• A basic description of potentiostat architectures can be found at http://www.consultrsr.com/resources/pstats/design.htm
• Thanks to Jack Summers, Benjamin Hickman, Craig Versek, Ian Walls, Jake Wheeler, and Todd Crosby

Uses

• Assess arsenic, cyanide, other contaminants / toxins in water
• Educational
• Identifying toxins / ingredients in foodstuffs

Development

• olm-pstat - repository for the PLOTS/PVOS Open Lab Monitor potentiostat peripheral
• source code from Jack Summers' DIY potentiostat

OHS2013_potentiostat_poster.svg

OHS2013_potentiostat_poster.pdf

Join the Discussion

on the Public Lab Potentiostat list

Background

Potentiostats are commonly used to test for the presence (via electrical activity) of particular compounds and microbes in solution, and thus have applications in environmental monitoring, food and drug testing, and many other areas. Typically, potentiostats are used in a research or industrial laboratory context for these purposes, and most commercially-available potentiostats are very expensive ($1000 is on the “cheap” side). There have been several initiatives in the last decade that have focused on designing cheaper alternatives; and when investigating technologies related to water quality assessment. Our aim here is to build on these efforts, and leverage the experise of the open hardware community in order to build a very accessible, and capable, device. Possible applications include:

• Tracking heavy metal concentrations in waterways. Various industrial processes used in the US and abroad can lead to the contamination of water with heavy metals that are dangerous to humans, like mercury and arsenic. An inexpensive, battery-powered potentiostat -- communicating over the cellular network, perhaps, or merely recording locally to an SD card -- might be able to track relative fluctuations in the concentrations of these metals, making monitoring these contaminants easier.

• A low-cost ‘field lab’ for evaluating water samples. An inexpensive potentiostat, when used according to the proper protocols, might be used to indicate absolute concentrations of heavy metals in water. This could allow citizens and organizations who can’t afford to send water samples to an expensive, bonded laboratory to do their own testing -- particularly relevant in a developing-world context.

• Education. Electrochemistry is an important part of many high school, college, and graduate chemistry curricula; an inexpensive potentiostat could render these curricula more accessible to educational institutions that don’t have the budget for the more expensive commercial versions.

• Research. Making an easily-hackable, programmable, and extensible potentiostat platform, based on a widely-used and well-supported technologies like the Arduino and the Raspberry Pi, could allow for novel electrochemistry applications in the laboratory; when a device that once cost $2000 and didn’t “play nice” with other hardware and software suddenly becomes available for under $200, and can be integrated with easy-to-use, open source software and hardware, researchers will likely dream up new approaches to open research problems -- and higher-throughput approaches in already-established research areas.

Details

Reference for the above "Adder Potentiostat" circuit: Bard, Allen J., and Faulkner, Larry R. Chap. 15: Electrochemical Instrumentation. Electrochemical Methods: Fundamentals and Applications, 2nd ed. John Wiley & Sons, Inc., 2001. pp. 632-658

A potentiostat is essentially a three terminal analog feedback control circuit that does its best to maintain a fixed voltage between the Working Electrode (WE) and Reference Electrode (RE) while sourcing current from the Counter Electrode (CE), perhaps within an electrochemical cell having load resistances that may change over time. In 3-probe electrochemical experiments, often the CE and WE are made of electrochemically inert conductive materials (we are using graphite, like from pencils, but platinum and gold are popular). The RE is typically a contraption designed to have a well-defined and stable electrochemical potential - an inexpensive one can be made from a piece of silver wire dipped in bleach; the Ag (metal) / AgCl (sparingly water soluble salt) couple electrode is sequestered in a glass tube with a saturated potassium chloride solution, which is fitted with a porous separator to allow ion exchange with the cell. Now by hooking up a power source the energy of electrons in the working electrode can raised and lowered with respect to the reference. Electrons can be made to hop onto certain chemical species, reducing them, or they can be pulled off, oxidizing them -- - the voltages (w.r.t. the RE) and currents at which reductions and oxidations happen can be measured, revealing information about the energies and concentrations of the analytes.

Work updates

• 8/5/2013: Craig Versek of PVOS has been building off a fully-fledged, open potentiostat design by Jack Summers. Craig is aiming to implement programmable current ranges. In this design, a CMOS analog multiplexer will switch out one of 5 standard current sense resistors (with room for 8 total), which are trimmer rheostats tuned to 250, 2.5k 25.0k 250k and 2.50M Ohms well within 0.5% margin of error.

References

• CheapStat
• Cornell U Potentiostat
• [Potentiostat Software on Github](http://bit.ly/15GQcKw

• A.V.Gopinath and D. Russell, "An Inexpensive Field Portable Programmable Potentiostat", Chem Educator, 2006. pp 23-28.

• Nice wikipedia description of what a potentiostat is here.

• A basic description of potentiostat architectures can be found at http://www.consultrsr.com/resources/pstats/design.htm
• Thanks to Jack Summers, Benjamin Hickman, Craig Versek, Ian Walls, Jake Wheeler, and Todd Crosby

Uses

• Assess arsenic, cyanide, other contaminants / toxins in water
• Educational
• Identifying toxins / ingredients in foodstuffs

Development

• olm-pstat - repository for the PLOTS/PVOS Open Lab Monitor potentiostat peripheral
• source code from Jack Summers' DIY potentiostat

OHS2013_potentiostat_poster.svg

OHS2013_potentiostat_poster.pdf

Background

Potentiostats are commonly used to test for the presence (via electrical activity) of particular compounds and microbes in solution, and thus have applications in environmental monitoring, food and drug testing, and many other areas. Typically, potentiostats are used in a research or industrial laboratory context for these purposes, and most commercially-available potentiostats are very expensive ($1000 is on the “cheap” side). There have been several initiatives in the last decade that have focused on designing cheaper alternatives; and when investigating technologies related to water quality assessment. Our aim here is to build on these efforts, and leverage the experise of the open hardware community in order to build a very accessible, and capable, device. Possible applications include:

• Tracking heavy metal concentrations in waterways. Various industrial processes used in the US and abroad can lead to the contamination of water with heavy metals that are dangerous to humans, like mercury and arsenic. An inexpensive, battery-powered potentiostat -- communicating over the cellular network, perhaps, or merely recording locally to an SD card -- might be able to track relative fluctuations in the concentrations of these metals, making monitoring these contaminants easier.

• A low-cost ‘field lab’ for evaluating water samples. An inexpensive potentiostat, when used according to the proper protocols, might be used to indicate absolute concentrations of heavy metals in water. This could allow citizens and organizations who can’t afford to send water samples to an expensive, bonded laboratory to do their own testing -- particularly relevant in a developing-world context.

• Education. Electrochemistry is an important part of many high school, college, and graduate chemistry curricula; an inexpensive potentiostat could render these curricula more accessible to educational institutions that don’t have the budget for the more expensive commercial versions.

• Research. Making an easily-hackable, programmable, and extensible potentiostat platform, based on a widely-used and well-supported technologies like the Arduino and the Raspberry Pi, could allow for novel electrochemistry applications in the laboratory; when a device that once cost $2000 and didn’t “play nice” with other hardware and software suddenly becomes available for under $200, and can be integrated with easy-to-use, open source software and hardware, researchers will likely dream up new approaches to open research problems -- and higher-throughput approaches in already-established research areas.

Details

Reference for the above "Adder Potentiostat" circuit: Bard, Allen J., and Faulkner, Larry R. Chap. 15: Electrochemical Instrumentation. Electrochemical Methods: Fundamentals and Applications, 2nd ed. John Wiley & Sons, Inc., 2001. pp. 632-658

A potentiostat is essentially a three terminal analog feedback control circuit that does its best to maintain a fixed voltage between the Working Electrode (WE) and Reference Electrode (RE) while sourcing current from the Counter Electrode (CE), perhaps within an electrochemical cell having load resistances that may change over time. In 3-probe electrochemical experiments, often the CE and WE are made of electrochemically inert conductive materials (we are using graphite, like from pencils, but platinum and gold are popular). The RE is typically a contraption designed to have a well-defined and stable electrochemical potential - an inexpensive one can be made from a piece of silver wire dipped in bleach; the Ag (metal) / AgCl (sparingly water soluble salt) couple electrode is sequestered in a glass tube with a saturated potassium chloride solution, which is fitted with a porous separator to allow ion exchange with the cell. Now by hooking up a power source the energy of electrons in the working electrode can raised and lowered with respect to the reference. Electrons can be made to hop onto certain chemical species, reducing them, or they can be pulled off, oxidizing them -- - the voltages (w.r.t. the RE) and currents at which reductions and oxidations happen can be measured, revealing information about the energies and concentrations of the analytes.

Work updates

• 8/5/2013: Craig Versek of PVOS has been building off a fully-fledged, open potentiostat design by Jack Summers. Craig is aiming to implement programmable current ranges. In this design, a CMOS analog multiplexer will switch out one of 5 standard current sense resistors (with room for 8 total), which are trimmer rheostats tuned to 250, 2.5k 25.0k 250k and 2.50M Ohms well within 0.5% margin of error.

References

• CheapStat
• Cornell U Potentiostat
• [Potentiostat Software on Github](http://bit.ly/15GQcKw

• A.V.Gopinath and D. Russell, "An Inexpensive Field Portable Programmable Potentiostat", Chem Educator, 2006. pp 23-28.

• Nice wikipedia description of what a potentiostat is here.

• A basic description of potentiostat architectures can be found at http://www.consultrsr.com/resources/pstats/design.htm
• Thanks to Jack Summers, Benjamin Hickman, Craig Versek, Ian Walls, Jake Wheeler, and Todd Crosby

Uses

• Assess arsenic, cyanide, other contaminants / toxins in water
• Educational
• Identifying toxins / ingredients in foodstuffs

Development

• olm-pstat - repository for the PLOTS/PVOS Open Lab Monitor potentiostat peripheral
• source code from Jack Summers' DIY potentiostat

OHS2013_potentiostat_poster.svg

OHS2013_potentiostat_poster.pdf

Background

Potentiostats are commonly used to test for the presence (via electrical activity) of particular compounds and microbes in solution, and thus have applications in environmental monitoring, food and drug testing, and many other areas. Typically, potentiostats are used in a research or industrial laboratory context for these purposes, and most commercially-available potentiostats are very expensive ($1000 is on the “cheap” side). There have been several initiatives in the last decade that have focused on designing cheaper alternatives; and when investigating technologies related to water quality assessment. Our aim here is to build on these efforts, and leverage the experise of the open hardware community in order to build a very accessible, and capable, device. Possible applications include:

• Tracking heavy metal concentrations in waterways. Various industrial processes used in the US and abroad can lead to the contamination of water with heavy metals that are dangerous to humans, like mercury and arsenic. An inexpensive, battery-powered potentiostat -- communicating over the cellular network, perhaps, or merely recording locally to an SD card -- might be able to track relative fluctuations in the concentrations of these metals, making monitoring these contaminants easier.

• A low-cost ‘field lab’ for evaluating water samples. An inexpensive potentiostat, when used according to the proper protocols, might be used to indicate absolute concentrations of heavy metals in water. This could allow citizens and organizations who can’t afford to send water samples to an expensive, bonded laboratory to do their own testing -- particularly relevant in a developing-world context.

• Education. Electrochemistry is an important part of many high school, college, and graduate chemistry curricula; an inexpensive potentiostat could render these curricula more accessible to educational institutions that don’t have the budget for the more expensive commercial versions.

• Research. Making an easily-hackable, programmable, and extensible potentiostat platform, based on a widely-used and well-supported technologies like the Arduino and the Raspberry Pi, could allow for novel electrochemistry applications in the laboratory; when a device that once cost $2000 and didn’t “play nice” with other hardware and software suddenly becomes available for under $200, and can be integrated with easy-to-use, open source software and hardware, researchers will likely dream up new approaches to open research problems -- and higher-throughput approaches in already-established research areas.

Details

Reference for the above "Adder Potentiostat" circuit: Bard, Allen J., and Faulkner, Larry R. Chap. 15: Electrochemical Instrumentation. Electrochemical Methods: Fundamentals and Applications, 2nd ed. John Wiley & Sons, Inc., 2001. pp. 632-658

A potentiostat is essentially a three terminal analog feedback control circuit that does its best to maintain a fixed voltage between the Working Electrode (WE) and Reference Electrode (RE) while sourcing current from the Counter Electrode (CE), perhaps within an electrochemical cell having load resistances that may change over time. In 3-probe electrochemical experiments, often the CE and WE are made of electrochemically inert conductive materials (we are using graphite, like from pencils, but platinum and gold are popular). The RE is typically a contraption designed to have a well-defined and stable electrochemical potential - an inexpensive one can be made from a piece of silver wire dipped in bleach; the Ag (metal) / AgCl (sparingly water soluble salt) couple electrode is sequestered in a glass tube with a saturated potassium chloride solution, which is fitted with a porous separator to allow ion exchange with the cell. Now by hooking up a power source the energy of electrons in the working electrode can raised and lowered with respect to the reference. Electrons can be made to hop onto certain chemical species, reducing them, or they can be pulled off, oxidizing them -- - the voltages (w.r.t. the RE) and currents at which reductions and oxidations happen can be measured, revealing information about the energies and concentrations of the analytes.

Work updates

• 8/5/2013: Craig Versek of PVOS has been building off a fully-fledged, open potentiostat design by Jack Summers. Craig is aiming to implement programmable current ranges. In this design, a CMOS analog multiplexer will switch out one of 5 standard current sense resistors (with room for 8 total), which are trimmer rheostats tuned to 250, 2.5k 25.0k 250k and 2.50M Ohms well within 0.5% margin of error.

References

• CheapStat
• Cornell U Potentiostat
• [Potentiostat Software on Github](http://bit.ly/15GQcKw
• Nice wikipedia description of what a potentiostat is here.
• A basic description of potentiostat architectures can be found at http://www.consultrsr.com/resources/pstats/design.htm
• Thanks to Jack Summers, Benjamin Hickman, Craig Versek, Ian Walls, Jake Wheeler, and Todd Crosby

Uses

• Assess arsenic, cyanide, other contaminants / toxins in water
• Educational
• Identifying toxins / ingredients in foodstuffs

Development

• olm-pstat - repository for the PLOTS/PVOS Open Lab Monitor potentiostat peripheral
• source code from Jack Summers' DIY potentiostat

OHS2013_potentiostat_poster.svg

OHS2013_potentiostat_poster.pdf

Background

Potentiostats are commonly used to test for the presence (via electrical activity) of particular compounds and microbes in solution, and thus have applications in environmental monitoring, food and drug testing, and many other areas. Typically, potentiostats are used in a research or industrial laboratory context for these purposes, and most commercially-available potentiostats are very expensive ($1000 is on the “cheap” side). There have been several initiatives in the last decade that have focused on designing cheaper alternatives; and when investigating technologies related to water quality assessment. Our aim here is to build on these efforts, and leverage the experise of the open hardware community in order to build a very accessible, and capable, device. Possible applications include:

• Tracking heavy metal concentrations in waterways. Various industrial processes used in the US and abroad can lead to the contamination of water with heavy metals that are dangerous to humans, like mercury and arsenic. An inexpensive, battery-powered potentiostat -- communicating over the cellular network, perhaps, or merely recording locally to an SD card -- might be able to track relative fluctuations in the concentrations of these metals, making monitoring these contaminants easier.

• A low-cost ‘field lab’ for evaluating water samples. An inexpensive potentiostat, when used according to the proper protocols, might be used to indicate absolute concentrations of heavy metals in water. This could allow citizens and organizations who can’t afford to send water samples to an expensive, bonded laboratory to do their own testing -- particularly relevant in a developing-world context.

• Education. Electrochemistry is an important part of many high school, college, and graduate chemistry curricula; an inexpensive potentiostat could render these curricula more accessible to educational institutions that don’t have the budget for the more expensive commercial versions.

• Research. Making an easily-hackable, programmable, and extensible potentiostat platform, based on a widely-used and well-supported technologies like the Arduino and the Raspberry Pi, could allow for novel electrochemistry applications in the laboratory; when a device that once cost $2000 and didn’t “play nice” with other hardware and software suddenly becomes available for under $200, and can be integrated with easy-to-use, open source software and hardware, researchers will likely dream up new approaches to open research problems -- and higher-throughput approaches in already-established research areas.

Details

Reference for the above "Adder Potentiostat" circuit: Bard, Allen J., and Faulkner, Larry R. Chap. 15: Electrochemical Instrumentation. Electrochemical Methods: Fundamentals and Applications, 2nd ed. John Wiley & Sons, Inc., 2001. pp. 632-658

A potentiostat is essentially a three terminal analog feedback control circuit that does its best to maintain a fixed voltage between the Working Electrode (WE) and Reference Electrode (RE) while sourcing current from the Counter Electrode (CE), perhaps within an electrochemical cell having load resistances that may change over time. In 3-probe electrochemical experiments, often the CE and WE are made of electrochemically inert conductive materials (we are using graphite, like from pencils, but platinum and gold are popular). The RE is typically a contraption designed to have a well-defined and stable electrochemical potential - an inexpensive one can be made from a piece of silver wire dipped in bleach; the Ag (metal) / AgCl (sparingly water soluble salt) couple electrode is sequestered in a glass tube with a saturated potassium chloride solution, which is fitted with a porous separator to allow ion exchange with the cell. Now by hooking up a power source the energy of electrons in the working electrode can raised and lowered with respect to the reference. Electrons can be made to hop onto certain chemical species, reducing them, or they can be pulled off, oxidizing them -- - the voltages (w.r.t. the RE) and currents at which reductions and oxidations happen can be measured, revealing information about the energies and concentrations of the analytes.

Work updates

• 8/5/2013: Craig Versek of PVOS has been building off a fully-fledged, open potentiostat design by Jack Summers. Craig is aiming to implement programmable current ranges. In this design, a CMOS analog multiplexer will switch out one of 5 standard current sense resistors (with room for 8 total), which are trimmer rheostats tuned to 250, 2.5k 25.0k 250k and 2.50M Ohms well within 0.5% margin of error.

References

• CheapStat
• Cornell U Potentiostat
• [Potentiostat Software on Github](http://bit.ly/15GQcKw
• Nice wikipedia description of what a potentiostat is here.
• A basic description of potentiostat architectures can be found at http://www.consultrsr.com/resources/pstats/design.htm
• Thanks to Jack Summers, Benjamin Hickman, Craig Versek, Ian Walls, Jake Wheeler, and Todd Crosby

Uses

• Assess arsenic, cyanide, other contaminants / toxins in water
• Educational
• Identifying toxins / ingredients in foodstuffs

Development

• olm-pstat - repository for the PLOTS/PVOS Open Lab Monitor potentiostat peripheral
• source code from Jack Summers' DIY potentiostat

Background

Potentiostats are commonly used to test for the presence (via electrical activity) of particular compounds and microbes in solution, and thus have applications in environmental monitoring, food and drug testing, and many other areas. Typically, potentiostats are used in a research or industrial laboratory context for these purposes, and most commercially-available potentiostats are very expensive ($1000 is on the “cheap” side). There have been several initiatives in the last decade that have focused on designing cheaper alternatives; and when investigating technologies related to water quality assessment. Our aim here is to build on these efforts, and leverage the experise of the open hardware community in order to build a very accessible, and capable, device. Possible applications include:

• Tracking heavy metal concentrations in waterways. Various industrial processes used in the US and abroad can lead to the contamination of water with heavy metals that are dangerous to humans, like mercury and arsenic. An inexpensive, battery-powered potentiostat -- communicating over the cellular network, perhaps, or merely recording locally to an SD card -- might be able to track relative fluctuations in the concentrations of these metals, making monitoring these contaminants easier.

• A low-cost ‘field lab’ for evaluating water samples. An inexpensive potentiostat, when used according to the proper protocols, might be used to indicate absolute concentrations of heavy metals in water. This could allow citizens and organizations who can’t afford to send water samples to an expensive, bonded laboratory to do their own testing -- particularly relevant in a developing-world context.

• Education. Electrochemistry is an important part of many high school, college, and graduate chemistry curricula; an inexpensive potentiostat could render these curricula more accessible to educational institutions that don’t have the budget for the more expensive commercial versions.

• Research. Making an easily-hackable, programmable, and extensible potentiostat platform, based on a widely-used and well-supported technologies like the Arduino and the Raspberry Pi, could allow for novel electrochemistry applications in the laboratory; when a device that once cost $2000 and didn’t “play nice” with other hardware and software suddenly becomes available for under $200, and can be integrated with easy-to-use, open source software and hardware, researchers will likely dream up new approaches to open research problems -- and higher-throughput approaches in already-established research areas.

Adder Potentiostat Circuit

Reference for the circuit: Bard, Allen J., and Faulkner, Larry R. Chap. 15: Electrochemical Instrumentation. Electrochemical Methods: Fundamentals and Applications, 2nd ed. John Wiley & Sons, Inc., 2001. pp. 632-658

Details

A potentiostat is essentially a three terminal analog feedback control circuit that does its best to maintain a fixed voltage between the Working Electrode (WE) and Reference Electrode (RE) while sourcing current from the Counter Electrode (CE), perhaps within an electrochemical cell having load resistances that may change over time. In 3-probe electrochemical experiments, often the CE and WE are made of electrochemically inert conductive materials (we are using graphite, like from pencils, but platinum and gold are popular). The RE is typically a contraption designed to have a well-defined and stable electrochemical potential - an inexpensive one can be made from a piece of silver wire dipped in bleach; the Ag (metal) / AgCl (sparingly water soluble salt) couple electrode is sequestered in a glass tube with a saturated potassium chloride solution, which is fitted with a porous separator to allow ion exchange with the cell. Now by hooking up a power source the energy of electrons in the working electrode can raised and lowered with respect to the reference. Electrons can be made to hop onto certain chemical species, reducing them, or they can be pulled off, oxidizing them -- - the voltages (w.r.t. the RE) and currents at which reductions and oxidations happen can be measured, revealing information about the energies and concentrations of the analytes.

Work updates

• 8/5/2013: Craig Versek of PVOS has been building off a fully-fledged, open potentiostat design by Jack Summers. Craig is aiming to implement programmable current ranges. In this design, a CMOS analog multiplexer will switch out one of 5 standard current sense resistors (with room for 8 total), which are trimmer rheostats tuned to 250, 2.5k 25.0k 250k and 2.50M Ohms well within 0.5% margin of error.

References

• CheapStat
• Cornell U Potentiostat
• [Potentiostat Software on Github](http://bit.ly/15GQcKw
• Nice wikipedia description of what a potentiostat is here.
• A basic description of potentiostat architectures can be found at http://www.consultrsr.com/resources/pstats/design.htm
• Thanks to Jack Summers, Benjamin Hickman, Craig Versek, Ian Walls, Jake Wheeler, and Todd Crosby

Uses

• Assess arsenic, cyanide, other contaminants / toxins in water
• Educational
• Identifying toxins / ingredients in foodstuffs

Development

• olm-pstat - repository for the PLOTS/PVOS Open Lab Monitor potentiostat peripheral
• source code from Jack Summers' DIY potentiostat

Background

Potentiostats are commonly used to test for the presence (via electrical activity) of particular compounds and microbes in solution, and thus have applications in environmental monitoring, food and drug testing, and many other areas. Typically, potentiostats are used in a research or industrial laboratory context for these purposes, and most commercially-available potentiostats are very expensive ($1000 is on the “cheap” side). There have been several initiatives in the last decade that have focused on designing cheaper alternatives; and when investigating technologies related to water quality assessment. Our aim here is to build on these efforts, and leverage the experise of the open hardware community in order to build a very accessible, and capable, device. Possible applications include:

• Tracking heavy metal concentrations in waterways. Various industrial processes used in the US and abroad can lead to the contamination of water with heavy metals that are dangerous to humans, like mercury and arsenic. An inexpensive, battery-powered potentiostat -- communicating over the cellular network, perhaps, or merely recording locally to an SD card -- might be able to track relative fluctuations in the concentrations of these metals, making monitoring these contaminants easier.

• A low-cost ‘field lab’ for evaluating water samples. An inexpensive potentiostat, when used according to the proper protocols, might be used to indicate absolute concentrations of heavy metals in water. This could allow citizens and organizations who can’t afford to send water samples to an expensive, bonded laboratory to do their own testing -- particularly relevant in a developing-world context.

• Education. Electrochemistry is an important part of many high school, college, and graduate chemistry curricula; an inexpensive potentiostat could render these curricula more accessible to educational institutions that don’t have the budget for the more expensive commercial versions.

• Research. Making an easily-hackable, programmable, and extensible potentiostat platform, based on a widely-used and well-supported technologies like the Arduino and the Raspberry Pi, could allow for novel electrochemistry applications in the laboratory; when a device that once cost $2000 and didn’t “play nice” with other hardware and software suddenly becomes available for under $200, and can be integrated with easy-to-use, open source software and hardware, researchers will likely dream up new approaches to open research problems -- and higher-throughput approaches in already-established research areas.

Adder Potentiostat Circuit

Reference for the circuit: Bard, Allen J., and Faulkner, Larry R. Chap. 15: Electrochemical Instrumentation. Electrochemical Methods: Fundamentals and Applications, 2nd ed. John Wiley & Sons, Inc., 2001. pp. 632-658

References

• CheapStat
• Cornell U Potentiostat
• [Potentiostat Software on Github](http://bit.ly/15GQcKw
• Nice wikipedia description of what a potentiostat is here.
• A basic description of potentiostat architectures can be found at http://www.consultrsr.com/resources/pstats/design.htm
• Thanks to Jack Summers, Benjamin Hickman, Craig Versek, Ian Walls, Jake Wheeler, and Todd Crosby

Uses

• Assess arsenic, cyanide, other contaminants / toxins in water
• Educational
• Identifying toxins / ingredients in foodstuffs

Development

• olm-pstat - repository for the PLOTS/PVOS Open Lab Monitor potentiostat peripheral
• source code from Jack Summers' DIY potentiostat

Background

Potentiostats are commonly used to test for the presence (via electrical activity) of particular compounds and microbes in solution, and thus have applications in environmental monitoring, food and drug testing, and many other areas. Typically, potentiostats are used in a research or industrial laboratory context for these purposes, and most commercially-available potentiostats are very expensive ($1000 is on the “cheap” side). There have been several initiatives in the last decade that have focused on designing cheaper alternatives; and when investigating technologies related to water quality assessment. Our aim here is to build on these efforts, and leverage the experise of the open hardware community in order to build a very accessible, and capable, device. Possible applications include:

• Tracking heavy metal concentrations in waterways. Various industrial processes used in the US and abroad can lead to the contamination of water with heavy metals that are dangerous to humans, like mercury and arsenic. An inexpensive, battery-powered potentiostat -- communicating over the cellular network, perhaps, or merely recording locally to an SD card -- might be able to track relative fluctuations in the concentrations of these metals, making monitoring these contaminants easier.

• A low-cost ‘field lab’ for evaluating water samples. An inexpensive potentiostat, when used according to the proper protocols, might be used to indicate absolute concentrations of heavy metals in water. This could allow citizens and organizations who can’t afford to send water samples to an expensive, bonded laboratory to do their own testing -- particularly relevant in a developing-world context.

• Education. Electrochemistry is an important part of many high school, college, and graduate chemistry curricula; an inexpensive potentiostat could render these curricula more accessible to educational institutions that don’t have the budget for the more expensive commercial versions.

• Research. Making an easily-hackable, programmable, and extensible potentiostat platform, based on a widely-used and well-supported technologies like the Arduino and the Raspberry Pi, could allow for novel electrochemistry applications in the laboratory; when a device that once cost $2000 and didn’t “play nice” with other hardware and software suddenly becomes available for under $200, and can be integrated with easy-to-use, open source software and hardware, researchers will likely dream up new approaches to open research problems -- and higher-throughput approaches in already-established research areas.

Adder Potentiostat Circuit

Reference for the circuit: Bard, Allen J., and Faulkner, Larry R. Chap. 15: Electrochemical Instrumentation. Electrochemical Methods: Fundamentals and Applications, 2nd ed. John Wiley & Sons, Inc., 2001. pp. 632-658

References

• CheapStat
• Cornell U Potentiostat
• [Potentiostat Software on Github](http://bit.ly/15GQcKw
• Nice wikipedia description of what a potentiostat is here.
• A basic description of potentiostat architectures can be found at http://www.consultrsr.com/resources/pstats/design.htm

Uses

• Assess arsenic, cyanide, other contaminants / toxins in water
• Educational
• Identifying toxins / ingredients in foodstuffs

Development

• olm-pstat - repository for the PLOTS/PVOS Open Lab Monitor potentiostat peripheral
• source code from Jack Summers' DIY potentiostat

Background

Potentiostats are commonly used to test for the presence (via electrical activity) of particular compounds and microbes in solution, and thus have applications in environmental monitoring, food and drug testing, and many other areas. Typically, potentiostats are used in a research or industrial laboratory context for these purposes, and most commercially-available potentiostats are very expensive ($1000 is on the “cheap” side). There have been several initiatives in the last decade that have focused on designing cheaper alternatives; and when investigating technologies related to water quality assessment. Our aim here is to build on these efforts, and leverage the experise of the open hardware community in order to build a very accessible, and capable, device. Possible applications include:

• Tracking heavy metal concentrations in waterways. Various industrial processes used in the US and abroad can lead to the contamination of water with heavy metals that are dangerous to humans, like mercury and arsenic. An inexpensive, battery-powered potentiostat -- communicating over the cellular network, perhaps, or merely recording locally to an SD card -- might be able to track relative fluctuations in the concentrations of these metals, making monitoring these contaminants easier.

• A low-cost ‘field lab’ for evaluating water samples. An inexpensive potentiostat, when used according to the proper protocols, might be used to indicate absolute concentrations of heavy metals in water. This could allow citizens and organizations who can’t afford to send water samples to an expensive, bonded laboratory to do their own testing -- particularly relevant in a developing-world context.

• Education. Electrochemistry is an important part of many high school, college, and graduate chemistry curricula; an inexpensive potentiostat could render these curricula more accessible to educational institutions that don’t have the budget for the more expensive commercial versions.

• Research. Making an easily-hackable, programmable, and extensible potentiostat platform, based on a widely-used and well-supported technologies like the Arduino and the Raspberry Pi, could allow for novel electrochemistry applications in the laboratory; when a device that once cost $2000 and didn’t “play nice” with other hardware and software suddenly becomes available for under $200, and can be integrated with easy-to-use, open source software and hardware, researchers will likely dream up new approaches to open research problems -- and higher-throughput approaches in already-established research areas.

Adder Potentiostat Circuit

Bard, Allen J., and Faulkner, Larry R. Chap. 15: Electrochemical Instrumentation. Electrochemical Methods: Fundamentals and Applications, 2nd ed. John Wiley & Sons, Inc., 2001. pp. 632-658

References

• CheapStat
• Cornell U Potentiostat
• [Potentiostat Software on Github](http://bit.ly/15GQcKw
• Nice wikipedia description of what a potentiostat is here.
• A basic description of potentiostat architectures can be found at http://www.consultrsr.com/resources/pstats/design.htm

Uses

• Assess arsenic, cyanide, other contaminants / toxins in water
• Educational
• Identifying toxins / ingredients in foodstuffs

Development

• olm-pstat - repository for the PLOTS/PVOS Open Lab Monitor potentiostat peripheral
• source code from Jack Summers' DIY potentiostat

Background

Potentiostats are commonly used to test for the presence (via electrical activity) of particular compounds and microbes in solution, and thus have applications in environmental monitoring, food and drug testing, and many other areas. Typically, potentiostats are used in a research or industrial laboratory context for these purposes, and most commercially-available potentiostats are very expensive ($1000 is on the “cheap” side). There have been several initiatives in the last decade that have focused on designing cheaper alternatives; and when investigating technologies related to water quality assessment. Our aim here is to build on these efforts, and leverage the experise of the open hardware community in order to build a very accessible, and capable, device. Possible applications include:

• Tracking heavy metal concentrations in waterways. Various industrial processes used in the US and abroad can lead to the contamination of water with heavy metals that are dangerous to humans, like mercury and arsenic. An inexpensive, battery-powered potentiostat -- communicating over the cellular network, perhaps, or merely recording locally to an SD card -- might be able to track relative fluctuations in the concentrations of these metals, making monitoring these contaminants easier.

• A low-cost ‘field lab’ for evaluating water samples. An inexpensive potentiostat, when used according to the proper protocols, might be used to indicate absolute concentrations of heavy metals in water. This could allow citizens and organizations who can’t afford to send water samples to an expensive, bonded laboratory to do their own testing -- particularly relevant in a developing-world context.

• Education. Electrochemistry is an important part of many high school, college, and graduate chemistry curricula; an inexpensive potentiostat could render these curricula more accessible to educational institutions that don’t have the budget for the more expensive commercial versions.

• Research. Making an easily-hackable, programmable, and extensible potentiostat platform, based on a widely-used and well-supported technologies like the Arduino and the Raspberry Pi, could allow for novel electrochemistry applications in the laboratory; when a device that once cost $2000 and didn’t “play nice” with other hardware and software suddenly becomes available for under $200, and can be integrated with easy-to-use, open source software and hardware, researchers will likely dream up new approaches to open research problems -- and higher-throughput approaches in already-established research areas.

Adder Potentiostat Circuit

Bard, Allen J., and Faulkner, Larry R. Chap. 15: Electrochemical Instrumentation. Electrochemical Methods: Fundamentals and Applications, 2nd ed. John Wiley & Sons, Inc., 2001. pp. 632-658

References

• CheapStat
• Cornell U Potentiostat
• [Potentiostat Software on Github](http://bit.ly/15GQcKw
• Nice wikipedia description of what a potentiostat is here.
• A basic description of potentiostat architectures can be found at http://www.consultrsr.com/resources/pstats/design.htm

Uses

• Assess arsenic, cyanide, other contaminants / toxins in water
• Educational
• Identifying toxins / ingredients in foodstuffs

Development

• olm-pstat - repository for the PLOTS/PVOS Open Lab Monitor potentiostat peripheral
• source code from Jack Summers' DIY potentiostat

OHS 2013

• Table - should have power
• Device - need to try chem experiment. Craig
• Experiment materials. Craig. Two sets of cables, to avoid contamination.
• Code - realtime plot in Python. Craig
• Serial library patch
• Applications: describe what this can do. Don
• Feedback/sign up form. Ian
• Cards with logo. In a week. Jake will order.
• Schematic. Craig or Don make SVG diagram. High level and lower level of feedback loop
• Data sample image - python output, Craig
• Reference list:
• electro-chemistry textbook
• Jack
• PVOS GitHub repo
• various current publications on potentiostats
• Instructions on setup - Ian will contact Kipp. Do we get free passes as demoers, or do we need to order tickets?
• PVOS logo into Badger form - Ian

Ref.: Bard, Allen J., and Faulkner, Larry R. Chap. 15: Electrochemical Instrumentation. Electrochemical Methods: Fundamentals and Applications, 2nd ed. John Wiley & Sons, Inc., 2001. pp. 632-658

Background

Potentiostats are commonly used to test for the presence (via electrical activity) of particular compounds and microbes in solution, and thus have applications in environmental monitoring, food and drug testing, and many other areas. Typically, potentiostats are used in a research or industrial laboratory context for these purposes, and most commercially-available potentiostats are very expensive ($1000 is on the “cheap” side). There have been several initiatives in the last decade that have focused on designing cheaper alternatives; and when investigating technologies related to water quality assessment. Our aim here is to build on these efforts, and leverage the experise of the open hardware community in order to build a very accessible, and capable, device. Possible applications include:

• Tracking heavy metal concentrations in waterways. Various industrial processes used in the US and abroad can lead to the contamination of water with heavy metals that are dangerous to humans, like mercury and arsenic. An inexpensive, battery-powered potentiostat -- communicating over the cellular network, perhaps, or merely recording locally to an SD card -- might be able to track relative fluctuations in the concentrations of these metals, making monitoring these contaminants easier.

• A low-cost ‘field lab’ for evaluating water samples. An inexpensive potentiostat, when used according to the proper protocols, might be used to indicate absolute concentrations of heavy metals in water. This could allow citizens and organizations who can’t afford to send water samples to an expensive, bonded laboratory to do their own testing -- particularly relevant in a developing-world context.

• Education. Electrochemistry is an important part of many high school, college, and graduate chemistry curricula; an inexpensive potentiostat could render these curricula more accessible to educational institutions that don’t have the budget for the more expensive commercial versions.

• Research. Making an easily-hackable, programmable, and extensible potentiostat platform, based on a widely-used and well-supported technologies like the Arduino and the Raspberry Pi, could allow for novel electrochemistry applications in the laboratory; when a device that once cost $2000 and didn’t “play nice” with other hardware and software suddenly becomes available for under $200, and can be integrated with easy-to-use, open source software and hardware, researchers will likely dream up new approaches to open research problems -- and higher-throughput approaches in already-established research areas.

References

• CheapStat
• Cornell U Potentiostat
• [Potentiostat Software on Github](http://bit.ly/15GQcKw
• Nice wikipedia description of what a potentiostat is here.
• A basic description of potentiostat architectures can be found at http://www.consultrsr.com/resources/pstats/design.htm

Uses

• Assess arsenic, cyanide, other contaminants / toxins in water
• Educational
• Identifying toxins / ingredients in foodstuffs

Development

• olm-pstat - repository for the PLOTS/PVOS Open Lab Monitor potentiostat peripheral
• source code from Jack Summers' DIY potentiostat

OHS 2013

• Table - should have power
• Device - need to try chem experiment. Craig
• Experiment materials. Craig. Two sets of cables, to avoid contamination.
• Code - realtime plot in Python. Craig
• Serial library patch
• Applications: describe what this can do. Don
• Feedback/sign up form. Ian
• Cards with logo. In a week. Jake will order.
• Schematic. Craig or Don make SVG diagram. High level and lower level of feedback loop
• Data sample image - python output, Craig
• Reference list:
• electro-chemistry textbook
• Jack
• PVOS GitHub repo
• various current publications on potentiostats
• Instructions on setup - Ian will contact Kipp. Do we get free passes as demoers, or do we need to order tickets?
• PVOS logo into Badger form - Ian