Theoretical and Experimental Studies of Electrochemical Impedance Based Micro Calorimetric Flow Sensor

In this paper, we propose a one-dimensional (1-D) analytical model for the Electrochemical Impedance (EI) based micro calorimetric flow sensor. Based on the parametric analysis of the developed 1-D model, two pairs of upstream and downstream gold electrodes are designed, in which the sensor is mainly fabricated on Cu on polyimide substrate (COP) with cost-reduction, by using a Flexible Printed Circuit (FPC) technology. The fabricated flexible and biocompatible EI flow sensor can measure 0.9 % NaCl solution flow in µm/s level (as low as 30 um/s), while its overheat temperature is less than 5 K, which is suitable for biomedical and in vivo applications. Besides, the testing results of this flexible flow sensor are in reasonable agreement with the theoretical prediction, which proves that the proposed 1-D model will be an effective tool for designing and optimizing the EI-based micro calorimetric flow sensor.