Bionic Flexible Wrinkled Strain Sensors With Water‑Accelerated Self‐healing Capability for Underwater Detection and Motion Interaction

Abstract

ABSTRACT Developing flexible sensors capable of long‐term, high‐sensitivity monitoring for flow fields and motion interactions is crucial for advancing unmanned underwater operations. However, flexible sensors always face challenges in achieving underwater superior self‐healing performance and high sensitivity simultaneously. Here, inspired by human skin, we present a method combining force‐driven wool spiral regulation with high‐temperature to fabricate a flexible sensor with random wrinkled microstructures. Importantly, the sensor resumed usable output within just 8 min of incurring damage because dynamic borate ester bonds were applied to accelerate its underwater self‐healing rate via hydrolysis‐re esterification reactions. This bionic self‐healing wrinkled flexible sensor achieves high underwater sensitivity, with average response and recovery time of only 124 ms and 112 ms, respectively, compared with most reported underwater flexible sensors with the same type of material of exceeding 200 ms. Notably, it maintains signal stability and functional continuity over 5,000 cycles following underwater self‐healing. We further demonstrated its use in underwater vehicle model and human motion for confirming its underwater continuously outputting stable and sensitive signals. These findings advance the underwater self‐healing flexible sensing units, with the potential to solve long‐term and high‐sensitivity condition monitoring towards underwater robotics, and water‐resistant human‐machine interfaces.