Mechanosensitive electronics aims at replicating the multifunctions of human skin to realize quantitative conversion of external stimuli into electronic signals and provide corresponding feedback instructions. Here, we report a mechanosensation-active matrix based on a direct-contact tribotronic planar graphene transistor array. Ion gel is utilized as both the dielectric in the graphene transistor and the friction layer for triboelectric potential coupling to achieve highly efficient gating and sensation properties. Different contact distances between the ion gel and other friction materials produce different triboelectric potentials, which are directly coupled to the graphene channel and lead to different output signals through modulating the Fermi level of graphene. Based on this mechanism, the tribotronic graphene transistor is capable of sensing approaching distances, recognizing the category of different materials, and even distinguishing voices. It possesses excellent sensing properties, including high sensitivity (0.16 mm-1), fast response time (∼15 ms), and excellent durability (over 1000 cycles). Furthermore, the fabricated mechanosensation-active matrix is demonstrated to sense spatial contact distances and visualize a 2D color mapping of the target object. The tribotronic active matrix with ion gel as dielectric/friction layer provides a route for efficient and low-power-consuming mechanosensation in a noninvasive fashion. It is of great significance in multifunction sensory systems, wearable human-machine interactive interfaces, artificial electronic skin, and future telemedicine for patient surveillance.
Keywords: direct-contact tribotronic devices; electronic skin; graphene transistor; mechanosensation; triboelectric nanogenerator.