An Electrochemical Impedance-Based Thermal Flow Sensor for Physiological Fluids

A novel electrochemical-thermal flow sensor was developed for use in physiological liquids. The sensor was constructed out of a platinum resistive heater and platinum sensing electrodes on a Parylene C substrate, rendering it flexible and fully biocompatible. During heating, changes in electrochemical impedance across the sensing electrodes were used to detect changes in temperature, and highly sensitive flow measurements were achieved with overheat temperatures of only 1 °C. The sensor's biocompatibility and low overheat temperature make it an ideal candidate for chronic in vivo applications.