Imagine that a metal structure is compressed and rolled up and automatically turned into its former useful shape when heated. This change is possible thanks to a liquid metal cage developed by researchers from Bingham University in the USA. From Bingham University, Assoc. Dr. Pu Zhang began his research using a metal known as Field alloy and cage-type structures produced with 3D printing. The alloy, named after its inventor chemist Simon Quellen Field, consists of a mixture of bismuth, indium and tin. The alloy only melts when heated to 62 degrees Celsius, but it re-solidifies after cooling. Using a technique known as vacuum casting and conformal coating, it covered the alloy cages with a layer of rubber. Research on liquid metals provides one-way deformation The alloy melts when heated and is held in a rubber exoskeleton. In this malleable form, the structures can then be pressed flat or transformed into another shape. The alloy hardens again when cooled, while retaining its modified form indefinitely. After this process, the alloy melts once again when the alloy is reheated above 62 degrees. Just as a rubber toy returns to its original shape after crushing, the rubber skeletons of the cages also return to their original shape and shape the liquid metal. After cooling, the alloy hardens back to its original state. The team used the technology to create items such as spider web-like mesh structures, soccer balls, honeycombs, and even a hand that opens as the alloy melts. The cage can also be used in applications such as the landing gear that can return to its original shape after being heated and cooled for the spacecraft. Zhang said, “The field alloy can collapse into it like other metals, but you can then heat it back to its former shape. Unlike other metals, you can use it over and over again.” says. The research was recently published in the journal Additive Manufacturing.
