Imagine a small autopilot driving on land, but suddenly squashed itself into a four axle aircraft and flew away. According to the research published in the latest issue of science robot, the American team has designed a new method to change the shape at the material level. It uses rubber, metal and temperature to deform the materials and fix them in a position without motors or pulleys. "When we started this project, we wanted a material that could do three things: change the shape, keep the shape, and then return to the original configuration and complete it in multiple cycles." Said Michael Bartlett, an assistant professor in the Department of mechanical engineering at Virginia Tech. In order to create a deformable structure, the team borrowed from the art of paper cutting. By observing the strength of these paper-cut patterns in rubber and composites, the team created a material structure with repeated geometric patterns. Next, the researchers developed a material that maintains the shape but allows the shape to be eliminated on demand. They introduced an inner skeleton made of low melting point alloy (lmpa) embedded in rubber skin. Usually, when the metal is stretched too far, the metal will permanently bend, break or stretch into a fixed and unusable shape. After the special alloy is embedded in the rubber, when stretched, the composite can quickly maintain the required shape, which is very suitable for flexible deformation materials that can bear load immediately. Finally, the material must restore the structure to its original shape. The team added a soft tendril heater next to the lmpa grid. The heater converts the metal into liquid at 60 ℃ or 10% of the melting temperature of aluminum. The elastomer skin keeps the molten metal in place, then pulls the material back to its original shape, torsion and tension, so that the composite has "reversible plasticity". When the metal cools, it again helps to maintain the shape of the structure. The researchers found that this paper-cut inspired composite design can create complex shapes, from cylinders to spheres to concave convex shapes. Shape change can also be realized quickly: after hitting with a ball, the shape changes and is fixed in place in less than 1 / 10 seconds. In addition, if the material breaks, it can be repaired many times by melting and reforming the metal inner skeleton. punctuate Many organisms in nature can change shape to perform different functions. For example, octopus can greatly change its shape to move, eat or interact with the environment; Humans can also bend muscles to support and maintain; Plants can move all day to catch the sun. But whether it can be realized in engineering is still unknown. Now, a deformed composite material is not only strong enough, but also easy to deform, so that the robot can maximize its adaptability to the environment. In the future, this material will bring us not only a new generation of robots performing multi-functional tasks, but also elastic devices that repair themselves after damage, which can stimulate rich applications in man-machine interface and wearable.