Each year, 3,500 button batteries are swallowed in the United States and now, a team of researchers from the Massachusetts Institute of Technology, the University of Sheffield and the Tokyo Institute of Technology have created an origami robot that might be able to help people in this situation.

The team conducted experiments involving a simulation of the human esophagus and stomach using a tiny origami robot. The robot, which can unfold itself from a tiny swallowed capsule, was steered by external magnetic fields and able to make its way across the stomach wall and retrieve a swallowed button battery and patch the wound.

"It's really exciting to see our small origami robots doing something with potential important applications to health care," said Daniela Rus, and a member of the research team and director of 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."

The robot's body design allows it to propel itself using a "stick-slip" motion, whereby appendages stick to a surface through friction through movement while still retaining the ability to slip free when it changes the weight distribution of its body.

Rus wasn't sure of the benefit of such a device until Shuhei Miyashita of CSAIL convinced her.

"Shuhei bought a piece of ham, and he put the battery on the ham," she said. "Within half an hour, the battery was fully submerged in the ham. So that made me realize that, yes, this is important. If you have a battery in your body, you really want it out as soon as possible."

"This concept is both highly creative and highly practical, and it addresses a clinical need in an elegant way," added Bradley Nelson, a professor of robotics at the Swiss Federal Institute of Technology Zurich. "It is one of the most convincing applications of origami robots that I have seen."

While the origami robot is currently controlled by an external magnetic field, the team hopes to eventually create one that can act and repair on its own.