Recent progress in soft robots: principles, designs, and applications

With advancements in the manufacturing industry persisting, soft robots have experienced rapid development, progressively emerging as a pivotal focus in the future trajectory of robotic technology. As a new type of robot technology, soft robots have significant differences from traditional robots in terms of principles, driving methods, design control, and other aspects. Here, we sort out and summarize the latest developments in soft robotics. Firstly, typical principles and driving methods were introduced, including rope drive, variable stiffness drive (gas negative pressure, intelligent fluids, etc), electromagnetic drive, and so on. Secondly, the main materials and characteristics of soft robots are analyzed, including hydrogels, shape memory alloys, photosensitive materials, electromagnetic rheological elastomer, biodegradable materials, etc. Then, typical soft robot structures and processing methods were introduced, including fluid static skeleton structures, muscle fluid static skeleton structures, and others. Finally, the problems of soft robots are analyzed, and the future development direction and importance are summarized. This paper highlights the recent progress in smart functional materials, typical biomimetic structures, and assembly methods applicable to soft robots, which is expected to assist the development and advancement of the next generation of soft robots.