Scientists have made a little origami robot that fits in a pill and could, one day, perform minor surgery inside your stomach.
It's been developed by researchers at the University of Sheffield, MIT, and the Tokyo Institute of Technology. The robot is a flat rectangle shape, about 2cm long when it unfolds. Its makers are presenting it at the International Conference on Robotics and Automation this week.
So far it's only been tested on an artificial stomach.
The researchers made a model of a pig's throat and stomach out of silicone rubber, then filled it with water and lemon juice to simulate the stomach acids. The pill is made of ice; once it melts, the little folded-up robot springs open.
It moves via a "stick-slip" motion – one part of the robot sticks to the stomach wall, while the rest slides along, a little like a caterpillar's crawl. It can also swim in the stomach fluids. "In our calculation, 20% of forward motion is by propelling water – thrust – and 80% is by stick-slip motion," Shuhei Miyashita, one of the researchers, said in a release.
What's a bit unusual about this robot is that it's largely made of pig intestine.
It's got two layers of dried pig gut, the stuff that makes the skin of a sausage, around an inner layer of a biodegradable plastic called Biolefin. It's also got a little magnet in it.
It's also unusual because it doesn't need a cord attaching it to the outside world. It's guided by magnets.
Daniela Rus of MIT, one of the researchers, said in a statement: "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." She said that she hopes later robots will be entirely autonomous and need no human control at all.
Dr Daniel Elson, a researcher at Imperial College London's Hamlyn Centre for technological medical research who didn't work on the robot, told BuzzFeed News that "if it can be made to work", the untethered system might have "loads of advantages": "The robot would be free to roam wherever it wants.
"But the amount of technological innovation required would be huge. It’s a very future-looking approach."
In the trial, the robot went into the artificial stomach and retrieved a button battery.
According to MIT, about 3,500 button batteries are swallowed in the US each year. They can cause significant injury if they leak or if they come into prolonged contact with the stomach wall – they then produce an electric current, which can create a corrosive chemical called peroxide out of your stomach fluids.
"Shuhei bought a piece of ham, and he put the battery on the ham," Rus 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."
The team says that the robot could also patch minor wounds or deliver medicines.
It's pretty cool, but any real-world applications are a long way off, and the methods we use now are already fairly effective.
"It's definitely a very blue-skies project," said Elson. "These sorts of robot developments have been attempted for many years.
"You need to look at whether it can have an impact clinically. It'd be competing with standard endoscopic approaches which work pretty well."
Tom Chivers is a science writer for BuzzFeed and is based in London.
Contact Tom Chivers at firstname.lastname@example.org.
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