Anti-Leakage Iontronic Pressure Sensor with Gradient Microcone Structures for Multifunctional Monitoring

Iontronic pressure sensors hold great promise for electronic skins and related fields, yet conventional single-microstructure designs struggle to balance sensitivity and linear range, whereas ionic leakage induces signal drift. Herein, we present a highly effective anti-leakage iontronic sensor featuring a surface gradient microcone array. The design leverages the progressive deformation of multilevel microstructures and immobilizes ionic liquids within a thermoplastic polyurethane matrix via hydrogen bonding and electrostatic interactions. By optimizing additives and microstructural parameters, we achieved synergistic control over electromechanical properties and response behavior. The sensor exhibits a high sensitivity of 209 kPa−1 over a wide linear range of 10−200 kPa (R2 = 0.997), an ultralow detection limit of 2 Pa, a high-pressure resolution of 12 Pa under an 8 kPa preload, and a low signal drift rate of 4.6% over 3000 cycles. Applications demonstrated include encrypted Morse code transmission, physiological signal monitoring, joint motion recognition, and detection of 5 to 30 μm microvibrations. This work provides a mechanochemical synergistic strategy for designing high-performance flexible pressure sensors.