Potentiostat

Team Members: Kyle BloomerJosh Geiman

Lucas Bennett

Team Sponsor: Dr. Cindy Harnett

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.

What is a Potentiostat?

Two past projects completed by a prior capstone group, and Ben Williams, a Masters student, both based on the “ardustat” project

Current design utilizes only two electrodes Noise issue with closing a dry contact relay,

especially when taking measurements moments after closure.

No circuit protection

Current design has a graphical user interface that has functionalities that are largely inoperable, and needs a ‘ground up’ revision

Past Potentiostat Projects

Developed by UCSB as an affordable alternative to OTS potentiostat devices

Three electrode configuration

Numerous measurement modes

Input parameters set through onboard LCD and 5-way joystick Our team plans to streamline the design, removing

these parts and passing configuration utility to the Data/Display Management System.

Cheapstat

Dr. Cindy Harnett's laboratory is in need of up to 15 potentiostats for testing a variety of electrochemical devices.

Off the shelf potentiostats range in price from $5-10k+, which necessitates an affordable alternative that can be both built and assembled by students.

Background Info

Must cost under $100

Must have the ability to measure Electrochemical potential

Must be easy for undergrad and graduate students to assemble and use

Must be well documented for future projects and maintenance

Project Requirements

ProcessorDevice Under

Test(DUT)

Data/Display Management

SystemUSB

120VAC60Hz15A

Voltage Converter

System Diagram

Function of system as an entity

Measures characteristics of electrolytic cells

Results of measurements reported from processor to Data/Display Management System through USB connection

Communicate results of test to user via Data/Display Management System

Function of System

ProcessorDevice Under

Test(DUT)

Data/Display Management

SystemUSB

120VAC60Hz15A

Voltage Converter

System Diagram

Processor Requirements Capturing the Configuration Execute the measurement set Report results of the measured set

ProcessorDevice Under

Test(DUT)

Data/Display Management

SystemUSB

120VAC60Hz15A

Voltage Converter

System Diagram

System control - provide the user with means to specify the appropriate parameters

Data logging - obtains records of the measurements returned from the Potentiostat

Data display - view results on the PC

Data/Display Management System Requirements

ProcessorDevice Under

Test(DUT)

Data/Display Management

SystemUSB

120VAC60Hz15A

Voltage Converter

System Diagram

“Wall Wart” 120VAC, 60Hz, 15A input power 5VDC, up to .5A output power

5VDC to 3.3VDC will be done on the PCB

If power consumption can be limited to 125mA input, Device can be powered via USB, eliminating this system component

Voltage Converter

The PC is connected to the potentiostat Software with a Graphical User Interface program will

run on a PC The user will have the ability to change configuration

of the test device through the GUI program to send to the potentiostat

Once the potentiostat is finished executing the test, the user will then receive the results through the software and have the ability to review them on the GUI.

Operational Concept

PC with USB connection

For the Potentiostat to communicate with the PC, a connection must be established through a USB interface

DC Power Converter

A DC power converter must be utilized within the system to allow 120VAC, 60Hz, and 15A of operational power

External Interfaces

USB Connection

Windows Operating System

Software to Software Interface

Internal Interface

Potentiostat Functional Requirements The Potentiostat manages two functions

Data communication

The function of this subcomponent is to communicate all data from the PC Interfacing Control to the Potentiostat system

Device Under Test (DUT) measurement

The Data/Display Management System will handle 4 main requirements through C# Program

Simplistic GUI for Data Controlling Transmit the configuration to the controller Initiates measurement process Retrieves raw data

Data/Display Management System Software

The PC Software will allow user to configure the test profile

The user will have the ability to select various waveforms and also set the maximum voltage applied by the potentiostat

The results of each measurement will then be reported back to the user

System Description

CheapStat Parts to be ordered today

Designing the GUI portion of the PC Software to best fit requirements

Testing preexisting Cheapstat

Current Status

Questions?