Bioinspired Suction Cup Arrays Enabling Intelligent Adhesion in Underwater Environments

Abstract

Biological adhesion represents a remarkable evolutionary adaptation, as exemplified by remoras using dorsal suction cups for hitchhiking and octopuses employing independently controllable suction cups to adhere to complex surfaces. Therefore, this study focuses on the design, quantitative analysis, and system-level construction of their artificial counterparts. Firstly, a reversible, low preload requirement, and multi-sensory suction cup array is fabricated and mounted on the dorsal of a bionic robotic fish. Notably, each channel of the suction cup array is independently controlled to enhance adaptability. Subsequently, five metrics are proposed to systematically measure and analyze the adhesion system. Specifically, the optimal structural parameters enable the miniaturized suction cup to achieve a pull-off force of 16 N on an acrylic plane, with the capability to adapt to varying surface radius and roughness. Furthermore, by leveraging sensory information and a hierarchical control strategy, we develop an autonomous adhesion method that enables the robotic fish to fine-tune the adhesion system according to varying surface characteristics and dynamically adjust under disturbed conditions. Finally, various aquatic experiments are conducted to validate the effectiveness and adaptability of the proposed adhesion system.