A bioinspired deep-sea iontronic skin for underwater robotic tactile sensing

Abstract

The non-destructive operation of intelligent underwater robotics with human-like sensory capabilities is essential for deep-sea resource exploration. However, extreme deep-sea hydrostatic pressure easily distorts sensor signals or damages devices, and detecting hundred-pascal-level contact forces under tens-of-megapascal hydrostatic pressures presents a critical challenge that hinders the advancement of underwater tactile sensing technology. Inspired by deep-sea sponges’ hydrostatic skeletal supporting mechanisms, we developed a fully open-pore hydrophobic ionogel as the sensing layer to construct a biomimetic deep-sea tactile sensor. The contact force is converted into electrical signals for object classification and non-destructive manipulation of marine organisms. This innovative sensing layer features aquatic stability and a pore structure balancing internal-external hydrostatic pressure, reducing environmental disturbances. The sensor maintains stable contact force detection under 50 MPa hydrostatic pressure, and accurately classify objects of varying hardness with an overall recognition accuracy of 95.5%, holding great potential for deep-sea exploration and sustainable resource exploitation.