Cilia-Inspired Magnetic Flexible Shear Force Sensors for Tactile and Fluid Monitoring

Recently, there has been a burgeoning interest in flexible shear force sensors capable of precisely detecting both magnitude and direction. Despite considerable efforts, the challenge of achieving accurate direction recognition persists, primarily due to the inherent structural characteristics and sensing mechanisms. Here, we present a shear force sensor constructed by a magnetically induced assembled Ni/PDMS composite membrane, which is magnetized and integrated with a three-axis Hall sensor, facilitating its ability to simultaneously monitor both shear force magnitude (0.7-87 mN) and direction (0-360°). The cilia-inspired shear force magnetic sensor (CISFMS) exhibits admirable attributes, including exceptional flexibility, high sensitivity (0.76 mN^-1), an exceedingly low detection limit (1° and 0.7 mN), and remarkable durability (over 10,000 bending cycles). Further, our results demonstrate the capacity of the CISFMS in detecting tactile properties, fluid velocity, and direction, offering substantial potential for future developments in wearable electronics.