1. Two-Electrode Results Three-Electrode Results
Two and Three Electrode Potentiostats
Three-Electrode Design
Sponsored By
Background Information
Dr. Harnett’s lab needs up to 15 potentiostats that are:
Inexpensive (less than $100 per unit)
Easy to assemble by students
OTS solutions range from $5K to $10K
Theory of Use
A potentiostat is:
The electronic hardware required to control a three electrode cell and run most electro-analytical experiments
An electronic instrument that controls the voltage difference between a Working Electrode and a Reference Electrode.
It measures the current flow between the Working and Counter Electrodes.
Design Methods
Two-Electrode Potentiostat
Previously developed by Capstone group during Fall 2010
Follow-on project by Ben Williams
Firmware improvements
Hardware component revision
Three-Electrode Potentiostat
Originally developed by University of California Santa Barbara
Cindy Harnett
Group Members: Kyle Bloomer, Luke Bennett, Josh Geiman
Experiment
Tested the current difference in four orange juice samples caused by varying amounts of ascorbic acid
0, 0.1, 0.2, and 0.3M of ascorbic acid in each sample, respectively
Electrode usage
Counter: Platinum wire
Working: Pencil “lead”
Reference: Standard Ag/AgCl
Processor Board
DDMS
Two-Electrode Results
Three-Electrode Results
Expected Results
Two-Electrode Design
Arduino
Development Board
Daughter Card
Conclusions and Recommendations
Results gathered from experiment do not coincide with expected results.
Possible contributing factors:
Reference electrode in poor condition
Possible firmware issues with measurement execution
Possible errors in chemistry related procedures
DDMS
Objectives
Improve existing Two-Electrode Potentiostat
Implement Three-Electrode Potentiostat
Test and compare results between designs