Diode-based CMOS MEMS thermal flow sensors

This paper reports on the intrinsic advantages of thermoelectronic flow sensors in comparison to their thermoresistive and thermoelectric counterparts. Hereafter, we will numerically and experimentally show that thermoelectronic flow sensors (i.e. thermal flow sensors employing p-n junction based devices as temperature sensors) benefit from the possibility of having the temperature sensor located in the hottest area of the heating element for enhanced convective effects and thus improved sensor sensitivity (Average Sensitivity +42%). Further improvements can be achieved by putting more diodes in series (Average Sensitivity +380%). A multidirectional thermoelectronic flow sensor is also reported.