Recent Advances on Underwater Soft Robots

Abstract

The ocean environment has enormous uncertainty due to the influence of complex waves and undercurrents. The human beings are limited in their abilities to detect and utilize marine resources without powerful tools. Soft robots employ soft materials to simplify the complex mechanical structures in rigid robots and adapt their morphology to the environment, making them suitable for performing some challenging tasks in place of manual labor. Due to superior flexible and deformable bodies, underwater soft robots have played significant roles in numerous applications in recent decades. Meanwhile, various technical challenges still need to be tackled to ensure the reliability and practical performance of underwater soft robots in complicated ocean environment. Nowadays, some researchers have developed underwater soft robotic systems based on biomimetics and other disciplines, aiming at comprehensive exploration of ocean and appropriate utilization of unexploited resources. This review presents the recent advances of underwater soft robots in the aspects of intelligent soft materials, fabrication, actuation, locomotion patterns, power storage, sensing, control, and modeling; additionally, the existing challenges and perspectives are analyzed as well.

Recent Progress in 3D Printing of Polymer Materials as Soft Actuators and Robots

“…13−17 Among these soft materials, hydrogels, shape memory polymers, and liquid crystalline elastomers have received increasing attention due to the versatile properties and functions. 3,9,13,18,19 These polymeric materials not only enable flexible design at macroscopic scales but also offer tailored functionalities by design at molecular and network levels. 20−23 Moreover, some specific functionalities, such as self-healing ability and degradability that hard materials rarely have, may increase the lifetime and sustainability of the soft robots and actuators, making them more close to biological organisms.…”

“…Their basic mechanical properties, processability, and biocompatibility are studied and compared with biological tissues . These soft materials with a high degree of design flexibility and rich stimulus-responsive characteristics favor the fabrication of soft robots to better mimic the structures of living organisms and perform a variety of complex actions. − Among these soft materials, hydrogels, shape memory polymers, and liquid crystalline elastomers have received increasing attention due to the versatile properties and functions. ,,,, These polymeric materials not only enable flexible design at macroscopic scales but also offer tailored functionalities by design at molecular and network levels. − Moreover, some specific functionalities, such as self-healing ability and degradability that hard materials rarely have, may increase the lifetime and sustainability of the soft robots and actuators, making them more close to biological organisms. − …”

“…In the recent two decades, a series of soft robots and actuators have been developed, greatly expanding the applications in biomedical and engineering fields. − The prosperity of this emerging area is inseparable from the innovations in new soft materials, advances in manufacturing techniques, and popular interdisciplinary research. In recent years, various soft materials have been developed by chemistry and materials scientists, providing abundant options to devise advanced soft actuators and robots through appropriate manufacturing technologies.…”

Steering characteristics and path following control of a bionic underwater vehicle with multiple locomotion modes

“…In order to accomplish above tasks, fast and efficient underwater path following control has crucial effects. Compared with traditional propeller-propulsion autonomous underwater vehicles (AUVs), bionic underwater vehicles inspired by biology have the advantages of superior efficient and maneuverable performances [1][2][3][4][5]. To this end, bionic underwater vehicles are more suitable for performing complex underwater tasks compared with traditional AUVs.…”