Femtosecond Laser Induced Supermetalphobicity for Design and Fabrication of Flexible Tactile Electronic Skin Sensor

Pursuing flexible tactile electronic skin sensors with superior comprehensive performances is highly desired in practical applications. However, current flexible tactile electronic skin sensors suffer insufficient flexibility and sensitivity, as well as high-cost and low-efficiency in fabrication and susceptible to contaminant in sensing performances. Here, a highly sensitive all-flexible tactile sensor (AFTS) is presented with capacitive sensing that combines double-side micropyramids dielectric layer and liquid metal (LM) electrode. The design and fabrication of LM-based AFTS are based on supermetalphobicity induced by femtosecond laser. The supermetalphobic micropyramids lead to high sensitivity up to 2.78 kPa-1, ultra-low limit of detection of ~ 3 Pa, fast response time of 80 ms, and excellent durability of cyclic load over 10000 times. The used femtosecond laser enables programmable, high-efficiency, low-cost, and large-scale fabrication of supermetalphobic double-side micropyramids, which is difficult to implement using conventional techniques. Furthermore, the outer substrates are treated by femtosecond laser, endowing the AFTS with excellent antifouling performance, and stable sensing signals in the highly humid environment. Successful monitoring of human physiological and motion signals demonstrates the potential of our developed AFTS for wearable biomonitoring applications.