MIT engineers have created a small folding robot. Swallowed in a capsule and directed from the outside by a magnetic field, it separates objects from the stomach.
Every year in the United States, 3,500 small flat batteries are swallowed. Although most of the time digestion eliminates them, they can get stuck in the esophagus or in the stomach. To be able to remove them, engineers at the Massachusetts Institute of Technology (MIT) have created a small robot, which folds to fit into a small, easy-to-swallow capsule.
Once in the stomach, the capsule melts and the released robot can deploy. To move in this hostile environment, it is directed by a magnetic field from outside the body. It uses the “glued and slipped” technique to move, changing its shape and its center of gravity: one side is glued to the wall, the robot unfolds, the center of gravity tilts forward, which becomes the new fulcrum, and the rear retracts. Put simply, it moves by “crawling” on the wall of the stomach.
The origami robot in action in a pig’s stomach (MIT video)
“To be able to act inside the body, you need a small controllable robot that is not docked,” explains Professor Daniela Rus of the electronics and computer department at MIT. It is very complicated to place a controlled device inside the body if it is connected to an external device. “
A robot that crawls and swims
To direct it, a small magnet was placed on the folding machine to react to the electromagnetic demands of the command system. When not stuck to the walls of the stomach, it uses small fins to move through stomach fluids.
Once at the location you are looking for, the robot can loosen a battery that may have installed itself. The device may seem disproportionate for a simple gobbling of batteries, but when they get blocked, the consequences are not trivial.
Heartburn that is not harmless
The electric current produced by the batteries can, quite quickly, damage the walls of the stomach by burning them. To convince Prof. Rus that this application was possible, a former post-doctoral fellow at MIT, Shuhei Miyashita, gave an eloquent demonstration.
“Shuhei bought a piece of ham, and put a stack on it,” explains Prof. Rus. In half an hour she was completely gone into the meat. It made me realize the importance of it: if you have a battery in your body, trust me, you want to get rid of it ASAP! “
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