Nanocomposite‐Enhanced Iontronic Tactile Sensor With High Sensitivity and Wide‐Range Linearity for Underwater Robotic Manipulation

Abstract

ABSTRACT Hydrostatic preload increases response nonlinearity and limits weak‐force detection in underwater tactile sensing. Here, we present a nanocomposite‐enhanced iontronic tactile sensor (NeITS) that combines high sensitivity with wide‐range linearity through a coupled mechano‐ionic mechanism. Hydrophobic SiO 2 nanoparticles reinforce the ionogel, suppress premature geometric saturation, and sustain contact‐area evolution, while pressure‐driven interfacial ion enrichment enhances electric double‐layer capacitance. The optimized sensor achieves a sensitivity of 55.36 kPa ─ 1 over a 500 kPa linear range, with response and recovery times of 50 ms. It resolves an additional contact pressure of approximately 2 kPa at hydrostatic preloads of 0, 93, and 116 kPa with closely comparable response amplitudes. A 4 × 4 NeITS array enables real‐time pressure mapping and shape imaging. Integrated into an underwater robotic gripper, the array supports neural‐network‐assisted recognition of nine representative benthic biological targets, achieving a mean classification accuracy of 97.8% under temporally separated window‐level evaluation. This work establishes a materials‐level strategy for hydrostatic‐pressure‐tolerant iontronic sensing and advances tactile perception for underwater robotic manipulation.