Ultra-thin, transparent and flexible tactile sensors based on graphene films with excellent anti-interference

Abstract

Tactile sensing, which can reflect the displacement of touch, is considered to be an essential function for electronic skin to mimic natural skin. Here we report a novel tactile sensor with good sensitivity, excellent durability and fast response based on highly flexible and transparent conductor layers. The tactile device is simple in terms of structure consisting of a pair of compliant conductive plates, which were adhered to graphene films (GFs) on the surface layer of the polyethylene terephthalate (PET) substrate, and a transparent elastic adhesive sandwiched between the electrodes. The as-assembled tactile sensors can reflect one-dimensional (1D) touch tactile. And the resistance of the device is linearly related to the tactile of touch. Notably, the rate of resistance change is up to 420% when the displacement is changed by 25 mm. The tactile sensor features a high sensitivity of 0.143 mm⁻¹, a long lifetime of 14 000 cyclic loading tests, and a fast response of 0.3 ms. Furthermore, the electrical signals of the tactile sensors are almost irrelevant to the interference signals such as vertical displacement, stress magnitude, stress acting area and bending strain. This rational design of innovative materials and devices presents great potential for electronic devices to completely replace the unique tough sensing properties of human skin.