Researchers from the University of Sheffield, Tokyo Institute of Technology, and MIT have teamed up to demonstrate a new foldable origami robot that can be ingested and then controlled inside the stomach to treat internal wounds or remove things like button batteries from the stomach. Button batteries are at times swallowed by children and can cause great injury if left alone. The ingestible robot starts in a digestible capsule that is swallowed.
Once in the stomach, that capsule dissolves and the robot unfolds itself and can then be steered by an external magnetic field to a specific location inside the stomach where it can treat injuries. “It’s really exciting to see our small origami robots doing something with potential important applications to health care,” says Daniela Rus, who also directs MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL). “For applications inside the body, we need a small, controllable, untethered robot system. It’s really difficult to control and place a robot inside the body if the robot is attached to a tether.”
This isn’t the first origami robot that MIT has developed, but this one is different from those previous designs. Previous origami robots used something called stick-slip to move which only works when the robot is stiff enough. One of the original folding robot designs used Mylar in its construction and was much stiffer than the current robot because the current bot is made with a biocompatible material.
To make the new robot stiffer, the design has fewer slits than previous bots. The new bot also relies on the fluid inside the stomach for propulsion. “In our calculation, 20 percent of forward motion is by propelling water — thrust — and 80 percent is by stick-slip motion,” says Shuhei Miyashita. “In this regard, we actively introduced and applied the concept and characteristics of the fin to the body design, which you can see in the relatively flat design.” In the center of one of the folds is a permanent magnet that responds to the changing magnetic field on the outside of the body.