Ultrasensitive, Fast-Responsive, Directional Airflow Sensing by Bioinspired Suspended Graphene Fibers.

ABSTRACT

The development of high-performance miniaturized and flexible airflow sensors is essential to meet the need of emerging applications. Graphene-based airflow sensors are hampered by the sluggish response and recovery speed and low sensitivity. Here we employ laser-induced graphene (LIG) with poststructural biomimicry for fabricating high-performance, flexible airflow sensors, including cotton-like porous LIG, caterpillar fluff-like vertical LIG fiber, and Lepidoptera scale-like suspended LIG fiber (SLIGF) structures. The structural engineering changes the deformation behavior of LIGs under stress, among which the synchronous propagation of the scale-like structure of SLIGF is the most conducive to airflow sensing. The SLIGF achieves the shortest average response time of 0.5 s, the highest sensitivity of 0.11 s/m, and a record-low detection threshold of 0.0023 m/s, benchmarked against the state-of-the-art airflow sensors. Furthermore, we showcase the SLIGF airflow sensors in weather forecasting, health, and communications applications. Our study will help develop next-generation waterflow, sound, and motion sensors.