A low-cost, handheld potentiostat device capable of high-resolution measurements and IOT connectivity

Potentiostats are essential instruments in electrochemical analysis, operating either by controlling the potential at the working electrode relative to a reference electrode and measuring the resulting current (potentiostatic mode) or by controlling the current and measuring the resulting potential (galvanostatic mode). The growing demand for portable potentiostats has been driven by applications in point-of-care diagnostics and on-site environmental monitoring. However, conventional potentiostats are often expensive, bulky or limited in the range of supported electrochemical techniques. This thesis presents Wedy50s, a low-cost, small form factor, battery-operated wireless potentiostat capable of performing multiple electrochemical techniques. The device integrates a Nordic NRF52840 as the main Microcontroller (MCU) and an AD5941 as the Analog Front End (AFE) device, enabling precise control and measurement in a small form factor. Wireless communication is facilitated via Bluetooth Low Energy (BLE), allowing the device to be controlled using a mobile application that supports configuration, operation, and data l ogging. Performance benchmarking was carried out against a lab-grade potentiostat (PalmSens4) in Cyclic Voltammetry (CV), chronoamperometry (CA), Square Wave Voltammetry (SWV), and Open Circuit Potential (OCP) measurements. Both devices were connected to standard glossy carbon Screen-Printed Electrodes (SPEs) that were immersed in a solution of ferri/ferrocyanide and potassium chloride to provide a balanced evaluation of their respective current responses. OCP measurements were conducted using wire electrodes and pH titration. The Wedy50s exhibited current responses comparable to the commercial system, with only minor deviations in the order of a few μA, likely due to signal smoothing in the reference device. Designed with portability in mind, the Wedy50s is powered by a single-cell Lithium-Ion (Li-ion) battery, which can be recharged wirelessly or by USB-C. Overall, the Wedy50s demonstrates performance comparable to lab-grade potentiostats, reliability, and versatility, highlighting its strong potential for a wide range of electrochemical applications.

Grantor dc:publisher

Stellenbosch : Stellenbosch University

Year dc:date.issued

2026

Author dc:creator

• Le Roux, Eckaard

Advisor dc:contributor.advisor

• Perold, W. J.

Language dc:language.iso

en

Repository record dc:identifier.uri

https://scholar.sun.ac.za/handle/10019.1/136292

OAI identifier oai:identifier

oai:scholar.sun.ac.za:10019.1/136292