Researchers at the University of Michigan in Ann Arbor have developed robots less than a centimeter in size that can form a shape, complete a task, then reconfigure into another shape for another task.
The team used the principals of origami to unlock the potential of the robots, which now can offer more use in fields such as medical equipment and infrastructure sensing.
“We’ve come up with a new way to design, fabricate, and actuate microbots,” says Evgueni Filipov, assistant professor of civil and environmental engineering. “We’ve been the first to bring advanced origami folding capabilities into one integrated microbot system.”
Most microbots have limited movements, which hampers their ability to perform tasks. To increase their range of motion, they need to be able to fold at large angles. U-M’s team has created microbots that can fold as far as 90 degrees and more. Larger folds allow microbots to form more complex shapes.
The microbots the U-M team created can complete their range of motion up to 80 times per second. While the devices often require an outside stimulus to activate, such as heat inside a body or a magnetic field applied to the device, U-M’s microbot uses a layer of gold and a layer of polymer that act as an onboard actuator, which requires no outside stimulus.
The U-M team’s devices currently are controlled by a tether, but eventually, they plan to add an onboard battery and a microcontroller that will apply an electric current in the systems.
“When current passes through the gold layer, it creates heat, and we use heat to control the motions of the microbot,” Filipov says. “We drive the initial fold by heating the system, then we unfold by letting it cool down. To get something to fold and stay folded, we overheat the system. When we overheat, we can program the fold – change where it comes to rest.”
The capabilities allow microbots to function elastically and plastically, giving them the ability to recover their original shape.
The research appears in Advanced Functional Materials and was supported by the Defense Advanced Research Projects Agency and the U-M College of Engineering Dean’s Fellowship.