Development of a Soft Gripper Capable of Controlling Buoyancy in Water

Underwater soft robots have the potential for a wide range of uses, including exploration, search, and rescue. In particular, the recently studied underwater soft robot is safer and more effective to employ than the current rigid robot since it can adapt easily to the environment. It also has a flexible and deformable body that allows it to adapt to challenging underwater environments and interact with various underwater creatures and structures. This soft gripper can manage buoyancy and shift its location in water up and down by changing the volume of the internal air without relying on an external device or mechanism. It is possible to function as a gripper while changing buoyancy in this situation. The gripper can grasp objects when the buoyancy is low and the amount of air content is little; conversely, when the amount of air is high and the buoyancy is low, the object can be carefully placed. The soft buoyancy gripper actuates using the stress differential between two soft polymers. When the soft polymer with relatively low elasticity is put on top of a thin, soft polymer that has been stretched and glued on both sides, the polymer can be rolled inward. In addition, when an air layer is formed between the two polymer layers, gripping and buoyancy can be controlled according to the amount of air injected into the device. At this point, several objects were held in place while the device's location in relation to the volume of air injected was examined. This will allow the soft robot to move in a small space and swim, crawl, and be utilized for a variety of tasks like environmental monitoring, search and rescue operations, and underwater exploration. Hence, this soft robot can carry out challenging duties by ascending and descending to different sea depths. The buoyancy control system of this underwater soft robot is an essential component that enables diversity and adaptability in water, and it has the potential to revolutionize underwater exploration and study. It has the benefit of being able to approach and operate intimately without hurting the marine environment and living organisms, which makes it particularly useful for ecological research and preservation. As a result, the described underwater soft robot may represent an innovative technology with numerous possible uses.<br/><br/>This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT) (No.2018R1A5A7023490), by the Korea Institute of Machinery and Materials (KIMM) funding (NK242C), and by the Ministry of Trade, Industry, and Energy (MOTIE) and the Korea Institute for Advancement of Technology (KIAT) through the International Cooperative R&D program (Project No. P0016173).