Controllable adhesion behavior in underwater environments

Abstract

Microstructure adhesive pads can effectively manipulate objects in underwater environments. Current adhesive pads can achieve adhesion and separation with rigid substrates underwater; however, challenges remain in the control of adhesion and detachment of flexible materials. Additionally, underwater object manipulation necessitates considerable pre-pressure and is sensitive to water temperature fluctuations, potentially causing object damage and complicating adhesion and detachment processes. Thus, we present a novel, controllable adhesive pad inspired by the functional attributes of microwedge adhesive pads, combined with a mussel-inspired copolymer (MAPMC). In the context of underwater applications for flexible materials, the use of a microstructure adhesion pad with microwedge characteristics (MAPMCs) is a proficient approach to adhesion and detachment operations. This innovative method relies on the precise manipulation of the microwedge structure's collapse and recovery during its operation, which serves as the foundation for its efficacy in such environments. MAPMCs exhibit self-recovering elasticity, water flow interaction, and tunable underwater adhesion and detachment. Numerical simulations elucidate the synergistic effects of MAPMCs, highlighting the advantages of the microwedge structure for controllable, non-damaging adhesion and separation processes. The integration of MAPMCs into a gripping mechanism allows for the handling of diverse objects in underwater environments. Furthermore, by merging MAPMCs and a gripper within a linked system, our approach enables automatic, non-damaging adhesion, manipulation, and release of a soft jellyfish model. The experimental results indicate the potential applicability of MACMPs in underwater operations.