A Triboelectric Sensor with High Sensitivity and Wide Detection Range by Tuning Electron Tunneling and Piezoelectric Charge

Triboelectric sensors have received extensive attention in wearable self-powered sensing, electronic skin, and smart medical treatment due to the characteristics of low-cost and diverse material choices, but the sensitivity and detected range are greatly limited to the development of scale and commercialization of triboelectric sensors. Herein, we propose a binary insulator/conductor electrification triboelectric sensor (BICS) assembling an aminated porous gelatin and aluminum (Al) as a positive tribolayer and an MXene@polyvinylidene fluoride (MXene@PVDF) nanofiber film as a negative tribolayer. Because of the positive layer, the Al can not only generate charges due to the triboelectric effect but also capture charges from gelatin due to the electron tunneling effect. And for the MXene@PVDF nanofiber negative layer, the MXene is embedded in PVDF film to enhance the generation of tribo- and piezocharge under contact with gelatin/Al film. Owing to the large number of charges generated, BICS shows an ultrahigh short current of 1.06 mA, which is 1000 times higher than previous related research (usually in ∼μA). BICS exhibits an excellent sensitivity of 3.33 V kPa^-1 and a wide detection range from Pa to kPa, making it ideal for full pressure scale human activity monitoring. Our findings provide a novel and significant strategy for constructing high-performance triboelectric sensors.