Fig. 7: Mobile liquid skin converts inanimate objects to miniature soft machines.

a The liquid skin turns silicone sheet into walking spiderbot. b The liquid skin turns silicone sheet into crawling caterpillarbot. c The liquid skin turns silicone sheet into swimming fishbot. d The upper left: the active liquid skin travels through a complex maze to reach the silicone sheet, which is transformed into a mobile robot through an adhesive strategy. The upper right: the robot moves from the bottom of the liquid to the surface of the liquid, and perform controlled movement on the surface. The lower left: the process of liquid skin adhering to the silicone sheet. The lower right: the process of the robot rising from the bottom to the surface. All the substrates are made of hydrogel. Scale bars, 10 mm.