On July 11th, National Science Review (shorted as NSR, IF 13.222) published online the paper “Bio-Inspired Untethered fully soft Robots in Liquid Actuated by Induced Energy Gradients” of the State Key Laboratory of Digital Manufacturing Equipment and Technology. MSE students Lv Liangxiong, Li Fen, Wu Kang are co-first authors. Professor Ding Han and Wu Zhigang are co-corresponding authors. Deng Pan, Seung Hee Jeong are also authors of the paper.
Soft robotics with new designs, fabrication technologies and control strategies inspired by nature have been totally changing people’s view on robotics. To fully exploit their potential in practical applications, untethered designs are preferred in implementation. However, hindered by the limited thermal/mechanical performance of soft materials, it has been always challenging for researchers to implement untethered solutions, which generally involve rigid forms of high energy-density power sources or high energy-density processes. A number of insects in nature, such as rove beetles, can gain a burst of kinetic energy from the induced surface energy gradient on water to return to their familiar habitats, which is generally known as Marangoni propulsion. Inspired by such a behavior, the researchers report agile untethered mobility of a fully soft robot in liquid based on induced energy gradients and also develop corresponding fabrication and maneuvering strategies.
The robot can reach a speed of 5.5 body lengths per second, which is 7-fold more than the best reported, 0.69 (body length per second), in the previous work on untethered soft robots in liquid by far. Further controlling the robots, the researchers demonstrate a soft robot swarm that can approach a target simultaneously to assure a hit with high accuracy. Without employing any high energy-density power sources or processes, this new robot exhibits many attractive merits, such as quietness, no mechanical wear, no thermal fatigue, invisibility and ease of robot fabrication, which may potentially impact many fields in the future.
The research is sponsored by the National Natural Science Foundation of China（No. U1613204，No. 91648000）.
Link to the paper: https://doi.org/10.1093/nsr/nwz083