The ingestible origami robot was developed by an international team of researchers from MIT, the University of Sheffield in the UK and the Tokyo Institute of Technology in Japan.
The device will be demonstrated at the International Conference on Robotics and Automation in Stockholm, Sweden May 16-21, 2016. The presentation builds on a long sequence of papers on origami robots from the research group of Daniela Rus, the Andrew and Erna Viterbi Professor in MIT’s Department of Electrical Engineering and Computer Science, according to MIT News.
In demonstrating how the robot works, the team says the device is folded into an ice capsule that when swallowed will melt when it reaches the warm fluids in the stomach. Then the device unfolds as if it were a piece of origami being filmed in reverse.
Once it is flat, like a piece of unfolded origami paper, it wiggles around the stomach, controlled by human operators using an external magnetic field. As one social media comment said, ” It is like aquarium cleaning magnets where you have one magnet in the tank and one outside that you use to make the one in the tank move.”
This device is not the first time origami applications have been used. They are actually a popular source of inspiration. But the ingestible robot did pose some interesting challenges. “For applications inside the body, we need a small, controllable, untethered robot system,” Rus explained in a statement, reports the Washington Post. “It’s really difficult to control and place a robot inside the body if the robot is attached to a tether.”
So that challenge was solved by attaching a tiny magnet to the robot. The robot is constructed of two layers of structural material to maintain the robot’s shape, with a layer of material made from dried pig intestine (the kind used in sausage casings) sandwiched in between the two layers. The dried pig intestine shrinks when heat is applied. Slits in the two outer layers allow the robot to fold like a small concertina when the inner material contracts.
The robot moves sort of like an inch-worm in what the research team calls a “stick-slip” motion. This means that the flattened device’s pointed corners, being designed for traction, reach forward, stick to the surface using traction and then draws the rest of itself forward. And because the stomach is full of liquids, the little robot can swim, too.
The team built a silicone synthetic stomach to demonstrate the device, modeling it on the mechanical structure of a pig’s stomach. It is filled with a solution of water and lemon juice to duplicate the acidity of the stomach contents. In demonstrations, the little robot made its way to a lithium button battery, and using its magnet was able to pick the battery up.
“It’s really exciting to see our small origami robots doing something with the potential for important applications to health care,” Rus said. Cnet reports that while it is too soon to say when the device will be ready for practical use, we need to remember that every three hours, a child in the U.S. swallows a lithium button battery, and this does occasionally lead to lethal outcomes.
