Researchers have developed tiny robots measuring less than 1 millimeter that start as a flat, hexagonal “metasheet.” However, when they receive an electrical charge, they transform into specific 3D shapes and begin to move.
Scientists at Cornell University have designed diminutive robots, each smaller than one millimeter, which are initially created in a 2D hexagonal “metasheet” form. With a quick surge of electricity, these robots change into programmed 3D shapes and start crawling.
The flexibility of these robots stems from an innovative design inspired by kirigami, an art similar to origami that includes cuts in the material. This technique allows the robots to fold, stretch, and move.
The team’s research, titled “Electronically Configurable Microscopic Metasheet Robots,” was published on September 11 in Nature Materials. The lead co-authors are postdoctoral researchers Qingkun Liu and Wei Wang, with the project supervised by Itai Cohen, a physics professor. His laboratory has previously developed microrobots capable of moving their limbs, pumping water with artificial cilia, and walking independently.
According to Liu, the inspiration for the kirigami robot came from “living organisms that are capable of changing shape.” He explained, “Typically, when robots are manufactured, they may be able to move parts of their limbs, but their overall appearance remains unchanged. Our creation is a metasheet robot. The term ‘meta’ refers to metamaterial, indicating that it’s made of numerous components that interact to produce specific mechanical properties.”
This robot features a hexagonal pattern made up of around 100 silicon dioxide panels linked by over 200 tiny actuating hinges, each just 10 nanometers thick. When electrically activated through external wires, these hinges can create folds that allow the robot to expand or contract its size by as much as 40%. By choosing which hinges to activate, the robot has the capability to take on different shapes and potentially wrap around objects before flattening back out again.
Cohen’s team is already exploring the future of metasheet technology. They hope to merge their flexible mechanical designs with electronic controllers to produce “elastronic” materials that are highly responsive and possess characteristics unattainable in the natural world. Potential uses for this technology include customizable micromachines, compact biomedical devices, and materials that react to impacts at near-light speeds rather than sound speeds.
Cohen added, “Since the electronics in each component can capture energy from light, we can design materials to react in programmed manners to various influences. For example, rather than simply deforming when touched, such materials could ‘escape’ or push back with more force than they received.” He believes that these active metamaterials—known as elastronic materials—could pave the way for a new category of intelligent materials governed by principles that exceed the capabilities of natural phenomena.
