Grid-free touch recognition on arbitrary surface using triboelectric vibration sensor

Touch panels are extensively applied across various fields, serving as a critical platform for the future of human-machine interaction and the metaverse. However, touch panel development is impeded by complicated sensor systems, including electrode grids, stacked multilayers, and external power. Here, a highly sensitive self-powered vibration sensor based on the triboelectric nanogenerator (VS-TENG) is designed to realize grid-free touch recognition on arbitrary surfaces by detecting and locating an external vibration source. The VS-TENG adopts a sensing structure composed of a dual-layer copper electrode designed with a parametric surface and a fluorinated ethylene propylene (FEP) film, enabling the detection of vibrations within the frequency range of 1-4500 Hz and sub-micron low-amplitude vibrations. The dual-layer electrode structure is beneficial to resist the interference from external environment. The output performance of the VS-TENG under various vibration frequencies, amplitudes, and directions, as well as its sensing capabilities when installed on panels of different materials and shapes, are systematically analyzed. The touch panel based on the VS-TENG can easily rearrange the touch resolution according to given scenarios without any physical modification to the sensor, enabling game control and vivid handwriting. This highlights its significant potential for diverse applications in the future metaverse.