A skin-inspired optoelectromechanically coupled system for 3-axis airflow sensor

Flexible airflow sensors that can detect the non-contact forces have broad prospects in environmental/climate monitoring, aircraft control, breathing monitoring, and human-computer interaction. Promising results have been achieved in terms of the sensing performances, however more challenging characteristics, such as the tunable detection range of airflow speed and 3-axis detection, are rarely investigated. Here, we demonstrate a skin-inspired optoelectromechanically coupled system, consisting of mechanically deformable elastic pillar array and photodetectors, for 3-axis airflow sensor. The mechanical deformation of elastic pillars induced by airflow can be optoelectrically coupled to photodetectors. As a result, variations in the collected photocurrent provide capabilities to quantitatively determine the speed of the incident airflow. Manipulating the Young’s modulus and filling factor of elastic pillar array leads to tunable effective detection range of airflow speed. Through the integration of the developed optoelectromechanically coupled system on a hemispherical substrate, as well as the deep neural network processing, 3-axis airflow sensing is demonstrated. Our study may open an avenue to develop the high-performance airflow sensor, which can be further extended to various types of optoelectrically-based multifunctional sensors or systems by integrating other functional materials.