The marriage between science fiction and current technology just got a little stronger as researchers at MIT announced an ingestible robot that unfolds inside the stomach and can be steered and controlled to remove dangerous swallowed objects like batteries or even perform internal surgery. If your kids (or drunk male friends) like putting small objects in their mouths, these are the droids you’re looking for.
Led by Daniela Rus, a professor in MIT’s Department of Electrical Engineering and Computer Science, researchers at MIT, the University of Sheffield, and the Tokyo Institute of Technology improved substantially on their earlier designs of an unfolding origami robot. According to their report to be presented at the International Conference on Robotics and Automation, creating a robot that can survive and operate in stomach acid presented a number of challenges.
The tightly-folded robot had to be small enough to fit inside a capsule frozen inside a small ice cube in order to be swallowable. Once inside the stomach, the material making up the origami robot had to be strong enough to open fully. The best material for walking inside a human stomach turned out to be, ironically, dried pig intestines – the same stuff used to make sausages. The wrapping is a biodegradable substance called Biolefin which shrinks when heated. The team settled on a rectangular robot whose accordion folds were perpendicular to its long axis and whose movement pivoted on pinched corners.
Protected inside one of the folds is a magnet that allows operators to control the robot’s movements from outside the body. The bot crawls around using a “stick-slip” technique where its tiny legs stick to an object or wall using friction, then “slips” off as it changes shape and redistributes its weight. In a demonstration, the bot used it own magnet to capture the swallowed battery.
Is swallowing batteries a problem that needs a robotic solution? According to the study, 3,500 button batteries are reportedly swallowed annually in the U.S. and thousands more go unreported. If they aren’t digested quickly, the batteries get electrically activated, producing hydroxide which destroys stomach and esophageal tissue. One team member used another part of a pig – ham – to illustrate the danger. A battery placed on a piece of ham ate its way completely into it in 30 minutes.
If all this talk about sausage and ham makes you hungry, check the snack bowl for batteries before grabbing a handful or you could end up with a bot in your belly hunting for it.