Multimodal Soft Amphibious Robots Using Simple Plastic-Sheet-Reinforced Thin Pneumatic Actuators.

A large challenge in the field of soft amphibious robotics is achieving high maneuverability and multiterrain adaptability through multimodal locomotion in hybrid terrestrial–aquatic environments. To address this issue, drawing inspiration from fruit-fly larvae and Spanish dancer sea slugs, a novel tethered soft amphibious robot with multimodal locomotion is proposed in this article, performing forward, backward, turning, and self-overturn motions both on land and in water. It leverages plastic-sheet-reinforced thin pneumatic actuators, which are constructed from thermoplastic membranes and embedded with a nonstretchable plastic sheet, enabling bidirectional bending with large angles. The robot achieves a forward jumping velocity of 1.77 BL/s and a forward swimming velocity of 0.69 BL/s, both faster than previously reported soft amphibious robots; connecting two actuator units in parallel, it achieves agile turning with a velocity of 111.8 $^\circ$ /s. Our proposed robot demonstrates exceptional multiterrain adaptability, facile terrestrial–aquatic transition capabilities, and underwater buoyancy adjustment ability. Especially when accidentally overturned, it can recover itself without external assistance, a capability rarely achieved by other soft robots.