Cornell University scientists have engineered microscale robots capable of morphing from flat sheets into complex 3D structures and moving. These miniature marvels, measuring less than 1 millimeter in size, represent a significant leap forward in the field of microrobotics.
The research team, led by Itai Cohen, professor of physics at Cornell, utilised a novel design based on kirigami, a variation of origami that involves cutting as well as folding. This approach allows the robots to change shape and locomote when stimulated by electrical current.
Qingkun Liu, a co-lead author of the study, explained the inspiration behind the project: "We were inspired by living organisms that can change their shape. But when people make a robot, once it's fabricated, it might be able to move some limbs but its overall shape is usually static."
The robot's structure consists of a hexagonal tiling composed of approximately 100 silicon dioxide panels, interconnected by over 200 actuating hinges, each only about 10 nanometers thick. When electrochemically activated, these hinges form mountain and valley folds, allowing the robot to change its shape and expand or contract by up to 40%.
This flexibility enables the microscale robot to adopt various configurations, potentially wrapping around objects and then unfolding back into a flat sheet. The team's design allows for preprogrammed 3D shapes to be achieved with precise electrical stimulation.
Looking to the future, Cohen's team is already considering the next phase of this technology. They aim to combine these flexible mechanical structures with electronic controllers to create "elastronic" materials with properties unprecedented in nature.
Potential applications for this technology are vast and exciting. Cohen envisions reconfigurable micromachines, miniaturised biomedical devices, and materials that can respond to impact at nearly the speed of light. "We think that these active metamaterials – these elastronic materials – could form the basis for a new type of intelligent matter governed by physical principles that transcend what is possible in the natural world," Cohen stated.