Highly Sensitive 2D Thermoresistive Micro Calorimetric Flow Sensor by Using $0.35\boldsymbol{\mu}\mathbf{m}$ CMOS MEMS Technology

Abstract

We report a two-dimensional (2D) Thermoresistive Micro Calorimetric Flow (TMCF) sensor by using a $0.35 \mu \mathrm{m}$ 2P4M CMOS MEMS technology. For the nitrogen gas flow, the fabricated 2D flow sensor achieves a prominent normalized sensitivity of 60.6 mV/W/(m/s). To overcome the sensor output drifting issue due to the locally redistributed fluid flow near the bonding wires, a digital signal conditioning algorithm by using the inverse distance weighting (IDW) method, instead of the conventional fitting with sine and cosine function, was proposed. Accordingly, this 2D flow sensor system shows the excellent velocity accuracy of ±4% and the angle accuracy of ±2°. Therefore, the fabricated highly sensitive 2D TMCF sensor will be a promising flow device for the smart buildings and the meteorological monitoring system.