The robot has no battery, chip, nor any other electronics. Health care workers can move it with a handheld magnet, while it glides through the stomach like a penguin on its belly. The researchers published their work May 8 in Science Advances.

Every year, millions of people worldwide are told they need an endoscopy. A doctor threads a camera on a tube down the throat to see what is wrong. It is uncomfortable, and in large parts of the world, it simply is not available. The soft robot SeroTab was built to change that. A doctor steers it with a magnet held against the skin. A standard ultrasound scanner reads the result from outside the body. The whole procedure could run in less than 20 minutes, at a clinic.