QEchemMEMS – A working electrode with high-resolution temperature sensing for studying electrochemical heat management systems

Abstract

Electrochemical heat pumps are a new and interesting concept for efficient thermal energy management at the micro- and macro-scale. The development of new solutions for electrochemical heat pumps requires reliable and high-resolution measurements of the temperature changes resulting from redox reactions. A device for measuring such temperature variations, manufactured using microelectromechanical system technology, is presented and characterized in this study. The device contains a platinum working electrode suspended on a thin SixNy membrane for the electrochemical cell; this electrode also serves as a resistive thermal device (RTD). The device and temperature readout electronic implementations of the Anderson loop are characterized. The temperature coefficient of resistance is 2736 ppm/K. The theoretical noise performance is predicted and verified in practice. The voltage noise of the RTD is 28 nV, which results in a temperature measurement resolution of 1.3 mK despite a very small RTD bias current of 40 µA.