A palm-like 3D tactile sensor based on liquid-metal triboelectric nanogenerator for underwater robot gripper

• Published in: Nano research Vol. 17; no. 11; pp. 10008 - 10016
• Main Authors: Li, Yuanzheng, Liu, Bo, Xu, Peng, Liu, Jianhua, Dai, Xirui, Yu, Aiqiang, Wang, Tianrun, Guo, Linan, Guan, Tangzhen, Song, Liguo, Xu, Minyi
• Format: Journal Article
• Language: English
• Published: Beijing Tsinghua University Press 01.11.2024
• Subjects: Accuracy; Aquatic mammals; Atomic/Molecular Structure and Spectra; Autonomous underwater vehicles; Biomedicine; Biomimetics; Biotechnology; Casting; Chemistry and Materials Science; Condensed Matter Physics; Contact angle; Damage detection; Design; Electric contacts; Feedback; Grasping (robotics); Grippers; Hydrogels; Liquid metals; Marine environment; Marine mammals; Materials Science; Nanogenerators; Nanotechnology; Noise sensitivity; Offshore structures; Research Article; Sensors; Shear forces; Silicones; Tactile sensors (robotics); Underwater; Underwater robots; Underwater structures; Vertical forces; Visual stimuli; distributed; triboelectric nanogenerator; tactile sensor; liquid metal; feedback control
• DOI: 10.1007/s12274-024-6903-3
• ISSN: 1998-0124

The highly sensitive and power efficient tactile sensors can provide grippers with vertical and shear forces from interactions with objects. In an ocean environment with low visual distance and high noise, sea otters can rely on their palms to accurately identify and grasp target objects without damage. Inspired by the structure of the sea otter’s palm, this paper proposes a distributed liquid metal-based three-dimensional biomimetic underwater triboelectric palm-like tactile sensor (UPTS) for feedback-controlled grippers. The device is mainly composed of a flexible shell, a flexible cover, a flexible support, a triboelectric sensing unit and a fixed shell. The force acting on the flexible cover causes the flexible cover and sensing unit to deform, so that the sensing unit undergoes a contact-separation process, thereby generating an electrical signal. UPTS has the capability to identify the magnitude and direction of force, with a direction recognition error angle within 5 degrees. Additionally, it can distinguish the hardness and shape of objects, achieving an accuracy rate of 100% and 99.75% respectively for the tested objects. The results indicate that UPTS can provide force feedback for underwater grippers, thereby assisting the grippers in better completing salvage task.