Low power, MEMS liquid flow sensor with silicone coating electrical insulation

A flow sensor based on a differential microcalorimeter integrated onto a silicon chip is presented. A tunable readout interface, capable of compensating for the sensor offset and offset drift, is integrated on the same chip as the sensing structures. The liquid flow is conveyed to the sensing structure by means of a proper package provided of micro-channels. A simple technique is used to deposit a silicone film onto the flow channel walls, including the chip surface exposed to the liquid. In this way electrical insulation between the sensing chip and the liquid flow is obtained. Results of test performed in deionized water flow are presented.