Fig. 2
From: A bioinspired multilegged soft millirobot that functions in both dry and wet conditions
Two different locomotion modes. a Discontinuous flap-wave (DFW) locomotion under the application of an “O” shape magnetic field in the “y–z” plane, under which the robot shows a “stick-slip” locomotion. As the magnetic bar is moved upper and forward, the robot raises its body corresponding to the front feet alignment to the magnetic flux. At the same time, the robot moves forward one step under the pulling force along the y axis. After the external magnetic field is off, all the robot’s feet are in touch with the ground again. Such a flap-wave locomotion is similar to a typical “stick-slip” movement widely used in piezo actuation at micro/nano scale. b Continuous inverted-pendulum (CIP) under the driving of an “S” shape magnetic field on “x–y” plane, under which the robot shows a “bipolar” locomotion-like human walking. The magnetic bar is programmed to move to the left and right directions alternately, meanwhile maintaining a forward movement. In response to the magnetic flux, the robot exhibits a continuous locomotion-like human walking, characterized by the alternate rise-up and continuous forward motion. c The robot’s step size at the CIP mode (277% feet length) is around three times longer than that at the DFW mode (94% feet length) in each gait cycle. It indicates that the CIP locomotion has a higher locomotion efficiency than that of the DFW, mainly because the robot can switch twice in one gait cycle continuously at the CIP mode, whereas only once at the DFW mode
