CMOS-Compatible MEMS 2D Thermal Flow Sensor With High Sensitivity and Low Power Consumption

In this letter, we present a CMOS-compatible MEMS micromachined and fully packaged two-dimensional (2D) thermal flow sensor. The sensor’s design parameters are determined by a nonlinear one-dimensional (1D) model. The fabricated 2D flow sensor features a $4\mu $ m thick suspended circular membrane and is further packaged into a bypass housing structure. Compared to state-of-the-art sensors, the packaged 2D flow sensor shows a higher normalized sensitivity of 50mV/(m/s)/W and low power consumption of less than 7mW. Besides, the developed sensor system achieved a measured angle error of less than 3° and an average velocity error of less than 4% for an input airflow of 0-30m/s within the full range of 360°. It also achieved a response time of <11ms across all airflow speeds. The experimental results conclude that the developed 2D flow sensor is promising for airflow measurement in smart buildings and meteorological monitoring systems.[2024-0048]