Scientists have created an ingestible origami robot that can unfold in a simulated stomach and retrieve a button battery.
Parents everywhere can soon rest easy as researchers from MIT, the University of Sheffield in the UK and the Tokyo Institute of Technology in Japan have created a tiny robot that can rescue button batteries from toddlers’ stomachs.
This revolutionary robot is a pill that, when swallowed, will open up and crawl across the stomach wall to retrieve button batteries with a magnet. It can even patch wounds.
In the USA, more than 3,500 incidents of button batteries being swallowed are reported annually, most of them involving children. Although most batteries can be safely ingested, they might sometimes leak and lead to tissue burns, bleeding and ultimately, death.
The origami robot is the latest development by the MIT Computer Science and Artificial Intelligence Laboratory headed by Daniela Rus, director, who has been researching and creating origami robots for years.
The idea of a robot that can be swallowed posed a number of challenges for Rus and the team.
“For applications inside the body, we need a small, controllable, untethered robot system,” Rus said. “It’s really difficult to control and place a robot inside the body if the robot is attached to a tether.”
The origami robot has a magnet attached to it, its movements controlled by external magnetic fields. There are two layers of structural material that make up the robot’s shape. The inner layer is constructed of material made of dried pig intestine, like the kind used in sausages. This material shrinks when heat is applied to it; slits in the two outer layers let the robot fold when the inner material contracts.
Its unique construction allows the robot to move along a surface in what the researchers call a “stick-slip” movement, similar to an inch worm. Its pointed corners will stick to surfaces using friction when it moves, then slips when the robot flexes again.
Since the stomach contains plenty of liquid, this robot can swim, too. First author Shuhei Miyashita, says that, “In our calculation, 20 percent of forward motion is by propelling water – thrust – and 80 percent is by stick-slip motion.”
The scientists built an artificial stomach out of silicone rubber, using the mechanical properties of a pig’s stomach as a model. They filled this “stomach” with water and lemon juice to mimic stomach fluids and deployed the origami robot in a capsule made of ice. The ice melted in the warm stomach environment, releasing the robot that crawled to a button battery and picked it up with its magnet.
“It’s really exciting to see our small origami robots doing something with potential important applications to health care,” Rus said.
The researchers will be presenting their creation at the IEEE International Conference on Robotics and Automation in Stockholm, Sweden in May 2016.