A human skin-inspired self-powered flex sensor with thermally embossed microstructured triboelectric layers for sign language interpretation

Flex sensors are essential for mechanosensation of human gesture monitoring, electronic skin development, and human-machine interfaces, but require a power supply for their operation. In this work, a highly sensitive and facile fabricated self-powered triboelectric flex sensor (STFS) is presented which can efficiently detect the finger bending motion and monitor the hand gestures. Drawn inspiration from the highly sensitive human skin dermisepidermis interlocked haptic performance, the fabricated STFS consists of randomly distributed microstructured (RDM) triboelectric layers imprinted from an emery paper through thermal embossing technology, achieving a high sensitivity of 0.77 VkPa(-1) along with rapid rise time of 83 ms and high stability (>100,000 loading unloading cycles). Also, the proposed flex sensor exhibits an ultrawide range of pressure detection from 0.2 kPa to 500 kPa. Moreover, a real-time application of sign language interpretation by detecting finger gestures and converting those gestures into voice and text through smartphone application is successfully demonstrated. This facile fabrication process paved a highly cost-effective, large scalable and time-efficient development of the self-powered flex sensor device with superior sensing properties, and high mechanical robustness for hand gesture monitoring and sign language interpretation system as well as human-machine interface application.