Impedance-driven capacitance amplification in dielectric gradient all-fiber non-ionic electronic skin

Non-ionic electronic skins offer intrinsic environmental stability, avoiding the leakage, volatility, and temperature sensitivity that limit ionic sensing systems. Yet, capacitive sensors based on electronic polarization typically exhibit low sensitivity because their dielectric modulation is confined to a single mode. Here, we introduce a dielectric-gradient, fully fiber-integrated non-ionic capacitive architecture that employs an impedance-driven enhancement mechanism. Controlled fiber deformation establishes a dual-variable dielectric network in which pressure-induced reduction of interfacial resistance and impedance releases suppressed polarization, yielding amplified capacitance far beyond that of conventional non-ionic sensors. The resulting device achieves ultrahigh sensitivity of 169.8 kPa^-1 over a wide range of 20 Pa-8 MPa and maintains stable operation from -80 °C to 200 °C with less than 6% deviation. When integrated into a tactile-sensing glove and combined with machine learning, it attains 99.25% accuracy in recognizing multiple operational tools under both cryogenic and high-temperature conditions. These findings establish impedance engineering as a universal strategy for constructing high-gain, thermally robust, and reliable non-ionic electronic skins, enabling precision tactile sensing in environments previously inaccessible to flexible electronics.