Multichannel Potentiostat with Shared Reference Electrode for Simultaneous Multitechnique Measurements in Microfluidic Sensor Arrays

Electrochemical measurements play a crucial role across various domains including air quality assessment, biological analysis, and the food industry. Miniaturized and power-efficient electrochemical potentiostats, facilitated by integrated circuits, have been instrumental in enabling wearable devices. However, the traditional CMOS potentiostat designs limit the simultaneous measurement of multi-sensor arrays within the same electrolyte solution where different bias potentials need to be applied to each sensor. Moreover, the utilization of modern integrated circuits with low supply voltage limits the applicability of electrochemical reactions requiring higher potential windows. This paper introduces an innovative potentiostat architecture that allows for sharing the reference electrode among multiple channels as well as expanding the voltage range for electrochemical cells. The novel potentiostat design is thoroughly described and results from a PCB prototype show strong output current linearity. Furthermore, verification of simultaneous measurements at different electrochemical bias conditions is presented and shown to match results from a commercial instrument.