Researchers at North Carolina State University have developed a groundbreaking class of robots known as “metabots” that are made from thin sheets of material. These robots have the unique ability to snap into hundreds of stable shapes, allowing them to perform a wide range of actions despite lacking traditional motors and being constructed from a single, flat material.
The metabots essentially resemble animated sheets of plastic that can move across surfaces and grasp objects. The researchers achieved this innovative design by incorporating thin films on the surface of polymer sheets, which respond to electricity or magnetic fields, serving as actuators to remotely change the shape of the robots.
Lead researcher Jie Yin, a professor of mechanical and aerospace engineering at NC State, explains, “We start out with simple polymer sheets that have holes in them, but by applying thin films to the surface of the polymer we’re able to incorporate materials that respond to electricity or magnetic fields. These films serve as actuators, allowing us to change the shape of the sheet remotely.”
By connecting multiple sheets together, the researchers were able to create structures that initially lie flat but can bend and fold into a wide variety of stable configurations. For example, connecting four sheets results in a metabot that can fold into 256 different stable states, despite starting as flat as a sheet of paper.
The research, published in Science Advances, showcases the versatility of these flat robots, which can move in various ways including jumping or crawling at different speeds. Caizhi Zhou, the first author of the paper and a Ph.D. student at NC State, notes, “The robots can change their shape and gait to adapt to different terrains or to perform a variety of functions, such as gripping and lifting objects.”
Furthermore, by incorporating piezoelectric materials into the thin films, the researchers can induce controlled vibrations in the metabots by adjusting the voltage and frequency. This additional control allows for more precise movements, such as rotating left or right while remaining stationary.
While this research is still in the early stages, the team believes it demonstrates a cost-effective and highly adaptable approach to robotics. Yin comments, “Our goal was to bridge metamaterials and robotics, and we think the results are promising.”
The study was a collaborative effort involving Ph.D. students Haitao Qing, Haoze Sun, and Fangjie Qi from NC State, as well as former Ph.D. student Yaoye Hong. The innovative design and capabilities of these metabots offer a glimpse into the future of robotics and materials science.
