Ionogel Fiber‐Based Flexible Sensor for Friction Sensing

Abstract The ability of flexible sensors to detect and recognize the perception of different mechanical stimuli is a prerequisite for meeting the challenges of flexible sensing in many applications. Although monitoring of frictional force and state is important and necessary, there is currently a shortage of highly sensitive sensors that can be used for frictional state sensing. This study demonstrates a high‐performance flexible sensor combining pyramidal micropatterns with ionogel nanofibers, which is capable of detecting both normal and tangential forces. The normal force is detected with a sensitivity of 1.145 kPa⁻¹, a response time of less than 30 ms, and a hysteresis of 3.8%. More importantly, the sensor enables sensitive recognition of sliding speed, normal force load, tangential force, and oil lubrication environments with different viscosities in a reciprocating friction condition. It also enables sensitive recognition of the entire relative sliding process from zero slip to stick‐slip. The excellent frictional force and state recognition performances and long durability of 600 cycles at high‐frequency reciprocating friction indicate that the ionogel fiber‐based flexible sensor has a great potential application in friction sensing.