A Current-Driven Potentiostat Architecture for Achieving Stability Over a Wide Range

The double-layer cell capacitance (C<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dl</inf>) in electrochemical sensing varies significantly, which is determined by the amount of redox reaction and the structure of an electrochemical cell. The traditional voltage-driven potentiostat architecture is stable only over a limited range of C<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dl</inf>, thus restricting its utility for wide-proliferated electrochemical cells. This paper proposes a current-driven potentiostat architecture that enhances the stability of the overall system across more than ten decades of C<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dl</inf>. The proposed architecture also works under a unipolar power supply, eliminating the need for bipolar supply voltages as required in the conventional voltage-driven potentiostat. The analog front end (AFE) of the proposed architecture has been developed on a printed circuit board (PCB), and its efficacy has been experimentally validated.