Origami Robot Retrieves Swallowed Objects

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When I was four years old I swallowed a Lego, because like most children, I held the firm belief that I should ingest anything that I could fit in my mouth—or at the very least, I should try. Two doctor’s visits, a lot of panic, and one spanking later, I learned not to trust things I couldn’t chew.

If only someone would invent an ingestible robot to perform a search-and-rescue mission for the innumerable wayward objects that have taken the long tumble down the gullets of the orally curious.

Oh, wait. Someone has.

Researchers at MIT and the Tokyo Institute of Technology have designed a tiny origami robot that can unfold from a swallowed capsule to retrieve debris from patients’ stomachs. The team will present the work at this week’s International Conference on Robotics and Automation.

The robot compresses with accordion-like folds into an easy-to-swallow ice capsule, which melts as it makes its way down the esophagus. Once the robot unfolds, it propels itself across the stomach lining in a “stick-slip” motion, steered by the shifting of magnetic fields outside of the body.

According to the researchers, over 3,500 button-sized batteries are ingested every year in the U.S. alone. Often, these batteries pose no risk to the individual who swallowed them. If the person’s stomach suffers prolonged exposure to the batteries, however, the metal releases hydroxide and burns through the tissue, resulting in serious abrasions. The origami robot, once completed, will locate and recover these batteries before they cause injury.

“It’s really exciting to see our small origami robots doing something with potential important applications to health care,” said Daniela Rus, one of the researchers from MIT’s Department of Electrical Engineering and Computer Science. “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.”

The study’s first author, Shuhei Miyashita, convinced Rus of the viability of developing the origami robot by purchasing a ham and placing a battery on its skin. Within half an hour, the battery had embedded itself into the meat entirely.

“That made me realize that, yes, this is important,” Rus recalled. “If you have a battery in your body, you really want it out as soon as possible.”

Additionally, the team hopes that the robot—or perhaps a new generation that builds upon the current research—could also be used to patch internal wounds or to deliver medicine at specific locations. Next, they hope to conduct in vivo experiments, and eventually, they will redesign the robot so that it can move autonomously, unaided by the external magnetic fields on which it currently relies.

To see how the ingestible origami robot works for yourself, take a look at MIT’s video: