High-performance e-skin based on bionic microstructures for physiological signal monitoring and remote sensing applications

Flexible tactile sensors have garnered increasing attention in artificial skin and robotics. However, the output signals of tactile sensors saturate rapidly after a certain pressure threshold, which is a stumbling block for diverse potential applications. Therefore, developing electronic skin (e-skin) capable of maintaining high sensitivity over a wide pressure range remains a challenge. To address this issue, we present a multi-layered graphite-PDMS film (MGPF) based e-skin, mimicking the gradient interlocking structures between the epidermis and dermis of biological skin. The novel design allows the e-skin sensor to detect a wide pressure range from 20 Pa to 600 kPa with a high sensitivity of 58.95 kPa⁻¹, simultaneously. At the same time, an excellent durability over 15 000 loading/unloading cycles is achieved. Additionally, we successfully demonstrate the application of e-skin in monitoring physiological signals. Furthermore, the e-skin is integrated into a microcontroller unit and the collected stimuli information can be wirelessly transmitted to a wearable display, showcasing its remote sensing capabilities. Finally, as a proof of concept, a smart glove is developed with the e-skin, which can wirelessly control the moving direction of a toy car, indicating the promising potential applications of the e-skin sensor in human-machine interactions.