Ultrahigh-transparency and pressure-sensitive iontronic device for tactile intelligence

Emerging tactile sensing devices mimic biological functions of human mechanoreception. By introducing the feature of optical transparency, it can lead to a combined capacities of tactile and visual intelligence into single system. Yet, it is difficult to realize ultrahigh level of optical transparency and device sensitivity in single structure, for the widely used methods for sensitivity improvement, such as elevating the interfacial roughness, may further reduce the transparency. By utilizing a transparent ionic material with tunable surface topologies, as well as introducing a strategy of refractive index matching, we have proposed a transparent iontronic sensing (TIS) device based on the iontronic sensing mechanism, simultaneously offering combined high device sensitivity (83.9 kPa −1 ), with ultrahigh optical transparency (96.9%), the highest reported value in literature. Benefiting from its comprehensive performance in sensing and optical characteristics, the TIS devices hold enormous potential for the human-machine interfaces for industrial and medical applications.