Swallowable robots can extract foreign objects

Economist : Each year in the US alone, more than 3500 people—primarily children—swallow button-cell batteries, which can burn holes in the stomach. Removing the batteries generally requires surgery. Now Daniela Rus and Shuhei Miyashita of MIT have developed a magnet-containing robot that can be placed inside a capsule and swallowed. Once the capsule dissolves, the robot unfolds itself and can be moved via magnetic fields from outside the body. After the robot latches onto the battery, the robot tows its haul to the intestine, from which the battery and robot are later excreted. A second robot can then be swallowed and moved to the location where the battery was found to deliver medication that speeds healing of any burns incurred. The team, which tested the robots in a transparent artificial stomach system, now plans to try them out on live pigs, a procedure that will require additional imaging systems to locate the battery and maneuver the robots.