Flexible and transparent sensors with hierarchically micro-nano texture for touchless sensing and controlling

Controlling electronic devices by touchless methods is a promising research field due to its application in healthcare, lifestyle monitoring, and human-computer interaction, providing users with more convenience and public safety. However, most of the functions are realized by capturing visual information using camera or radar sensors. Here, we demonstrate a flexible and relatively transparent touchless sensor achieving non-contact controlling on a single sensor pixel based on the surface charge redistributions under hand motions. Moreover, the optimized surface design method is analyzed and the output signals are increased by more than 200% after hierarchically nano-micro textures are fabricated on the sensing layer, providing the device with higher sensitivity. We further present the practical application of such sensors to skip or zoom a picture without laying fingers on the screen of computer, even under though-obstacle situations. This not only suggests promising applications of non-contact controlling methods but also presents a strategy for signal enhancement of near-field sensing technology.