Development of an All-Polyimide Flexible Airflow Sensor for Flow-Velocity and Flow-Direction Sensing

Abstract

In this study, we developed an all-polyimide flexible airflow sensor, which consisted of four hair-like curved polyimide (PI) cantilever beams arranged in a cross-form configuration and graphene/polyimide (Gr/PI) nanocomposite-based piezoresistors. Electrical breakdown process was applied to fabricate the Gr/PI nanocomposite-based piezoresistors . As airflow travels through the cross-form configuration hair-like curved cantilevers, the cantilever beams will be deformed, which leads to a corresponding change in the resistances of the piezoresistors. As the hair-like airflow sensor is fully flexible, it can fit on curved surfaces. To compensate the ambient temperature fluctuation on the measurement accuracy of flow velocity, a temperature sensor is integrated nearby the cantilevers. The sensor is designed to have the ability of measuring both the flow velocity and flow direction, which is very crucial to many practical applications.