Reliability Investigation of Bioinspired Hair Flow-Sensor

In capacitive MEMS sensors, the excitation voltage is necessary for operating the device and increasing the sensitivity. For reliable operation, the amplitude of the excitation voltage is restricted by the pull-in voltage of the sensor. This paper investigates the pull-in phenomenon associated with the capacitive sensing mechanism of artificial hair flow-sensor (HFS), as an important design parameter to improve reliability, robustness, and sensitivity of the sensor. The pull-in voltage of the HFS is investigated theoretically and verified experimentally. The electrostatic force acting on the membrane, the pull-in voltage, and the deflection of the membrane for different excitation voltages are considered. The theoretical model together with the HFS design parameters is used to inspect the possible origin for the deviation between the theory and the experiments. Furthermore, we pointed out and stated the applicable conditions of the HFS based on the experimental results and theoretical analysis. Such a study forms a step further to improve the reliability of the HFS to be a suitable candidate for the utilization at different conditions and in various applications.