Self-Powered Liquid Metal Machine

With the development of materials and the increasing demand for their use, research on flexible machines has become a major trend. Gallium and its alloys, as a typical class of liquid metals, may provide new ideas for the soft machine with their unique mobility and electrical properties. The present laboratory has discovered for the first time the self-powered mechanism of a synthetic motor based on liquid metals. The liquid metal motor starts to move in the form of a transformable motor after swallowing a small amount of matter, with a speed of centimeters per second and a lifetime of more than 1 h. Unlike conventional motors, the liquid metal motor can deform itself depending on the space it is in. At the same time, such machines do not require an external electrical supply; they use aluminum as “food” and can spontaneously convert chemical energy into mechanical energy. Based on the self-running machine formed by the liquid metal swallowing aluminum, researchers have developed a variety of related cutting-edge applications, such as self-powered pumps, periodic switching elements, and transformable wheeled drug carriers. In this chapter, the principles and applications of self-powered liquid metal machines are presented, including the design of operating channels and substrates, the working mechanism of motors, and practical application cases. Obviously, the discovery of liquid metal self-powered effects and the corresponding machine forms opens up a whole new path for the development of more complex reconfigurable intelligent robots.