A Versatile Soft Crawling Robot with Rapid Locomotion.

This article presents a versatile soft crawling robot capable of rapid and effective locomotion. The robot mainly consists of two vacuum-actuated spring actuators and two electrostatic actuators. By programming the actuation sequences of different actuators, the robot is able to achieve two basic modes of locomotion: linear motion and turning. Subsequently, we have developed analytical models to interpret the static actuation performance of the robot body, including linear and bending motions. Moreover, an empirical dynamic model is also developed to optimize the locomotion speed in terms of frequency and duty cycle of the actuation signal. Furthermore, with the help of the strong electroadhesion force and fast response of the deformable body, the soft robot achieves a turning speed of 15.09°/s, which is one of the fastest among existing soft crawling robots to the best of our knowledge. In addition to the rapid and effective locomotion, the soft crawling robot can also achieve multiple impressive functions, including obstacle navigation in confined spaces, climbing a vertical wall with a speed of 6.67 mm/s (0.049 body length/s), carrying a payload of 69 times its self-weight on a horizontal surface, crossing over a 2 cm (0.15 body length) gap, and kicking a ball.