3D Printed Bio-Inspired Hair Sensor for Directional Airflow Sensing

Abstract

With reduction in the scale of unmanned air vehicles, there is an increasing need for lightweight, compact, low-power sensors and alternate sensing modalities to facilitate flight control and navigation. This paper presents a novel method to fabricate a micro-scale artificial hair sensor that is capable of directional airflow sensing. The sensor consists of a high-aspect ratio hair structure attached to a thin flexible membrane. When subjected to airflow, the hair deflection induces a deformation of the membrane. Two pairs of perpendicular electrodes are attached to the membrane, which allow the sensing of airflow amplitude and direction through the measurement of differential capacitance. The sensor structure is fabricated by using two photon polymerization, which is integrated onto a miniature PCB circuit board to allow simple measurement. The sensor's responses to static displacement loading from different directions were characterized, and are in good agreement with the simulation results. Finally, the sensor's capability for directional airflow measurement was demonstrated with a clear correlation between flow speed and sensor output.