Recent progress on underwater soft robots: adhesion, grabbing, actuating, and sensing

Abstract

The research on biomimetic robots, especially soft robots with flexible materials as the main structure, is constantly being explored. It integrates multi-disciplinary content, such as bionics, material science, mechatronics engineering, and control theory, and belongs to the cross-disciplinary field related to mechanical bionics and biological manufacturing. With the continuous development of various related disciplines, this area has become a hot research field. Particularly with the development of practical technologies such as 3D printing technology, shape memory alloy, piezoelectric materials, and hydrogels at the present stage, the functions and forms of soft robots are constantly being further developed, and a variety of new soft robots keep emerging. Soft robots, combined with their own materials or structural characteristics of large deformation, have almost unlimited degrees of freedom (DoF) compared with rigid robots, which also provide a more reliable structural basis for soft robots to adapt to the natural environment. Therefore, soft robots will have extremely strong adaptability in some special conditions. As a type of robot made of flexible materials, the changeable pose structure of soft robots is especially suitable for the large application environment of the ocean. Soft robots working underwater can better mimic the movement characteristics of marine life in the hope of achieving more complex underwater tasks. The main focus of this paper is to classify different types of underwater organisms according to their common motion modes, focusing on the achievements of some bionic mechanisms in different functional fields that have imitated various motion modes underwater in recent years (e.g., the underwater sucking glove, the underwater Gripper, and the self-powered soft robot). The development of various task types (e.g., grasping, adhesive, driving or swimming, and sensing functions) and mechanism realization forms of the underwater soft robot are described based on this article.

Additive Manufacturing in Underwater Applications

“…For the design of this type of vehicle, 3D printing technology is necessary, because it requires non-typical elements [23,111]. The same applies for other bio-inspired soft robots [114][115][116].…”

Continuum Robots and Magnetic Soft Robots: From Models to Interdisciplinary Challenges for Medical Applications

“…With the development of new materials and driving technology, soft robots applications are like changes in traditional transportation [ 1 , 2 , 3 , 4 , 5 ]. In recent years, the study of soft robotics has garnered widespread attention, primarily focusing on applications in medical fields [ 6 , 7 ], underwater robotics [ 8 , 9 , 10 , 11 , 12 ], manipulation and grasping [ 13 , 14 ], space exploration [ 15 ], and operations in confined spaces [ 16 , 17 , 18 , 19 ]. Given the diverse range of soft robots, this paper primarily concentrates on applying continuum robots (the robot structure has a flexible continuum backbone ( Figure 1 (1-0a)) or an equivalent continuum backbone) and magnetic soft robots (robots embedding magnetic media in soft materials ( Figure 1 (1-0b))) in medical settings ( Figure 1 (1-1)).…”

Development of a pump-jet piezoelectric swimmer with acoustic radiation actuation

“…operations [1][2][3]. Because of the bulky transmission gears and noise, the traditional driving devices combining electromagnetic motors and propellers are gradually difficult to meet the requirements of miniaturization and portability [4][5][6].…”