Triboresistive Touch Sensing—Grid-Free Touch Point Recognition Based on Monolayered Ionic Power Generators

Recent growing pursuit of skin-mountable devices has been impeded by complicated structures of most sensing systems, containing electrode grids, stacked multi-layers, and even external power sources. Here, we introduce a type of touch sensing, termed triboresistive touch sensing, for gridless touch recognition based on monolayered ionic power generators in Fig. 1. A homogeneous monolayer, i.e. ionic PDMS, generates electricity based on the electric field generated by touch. Voltages generated at each corner of ionic PDMS relied on resistance between touch points and each corner, ensuring recognition of the touch positions without need for electrode grid layers and external power sources. With notable advantages of high transparency (96.5%), stretchability (539.1%), and resilience (99.0%) of the ionic PDMS, epidermal triboresistive sensing was demonstrated to express touch position and readily play a musical instrument. Gridless system of triboresistive sensing allowed to rearrange touch sections according to a given situation without any physical modification, and thus easily completed consecutive missions of controlling position, orientation, and gripping functions of a robot.