The robotic penguin that makes endoscopy optional

Monday 11 May 2026

Researchers at the TechMed Centre of the University of Twente have built a swallowable soft robot that samples stomach fluid and measures acidity in real time. The robot has no battery, chip, nor any other electronics. Healthcare 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 today 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 under twenty minutes, at a clinic.

A stomach exam without the camera

SeroTab contains a gel that swells when it contacts stomach acid. Special discs inside the gel make that swelling measurable with a standard ultrasound scanner, from outside the body. No tube down the throat needed.

The device can also collect a gastric fluid sample on command. A radio wave activates a small pump inside SeroTab, which draws fluid into an internal chamber. That chamber is retrieved after the procedure and sent to a lab for analysis.

No electronics.

Getting SeroTab to the right spot is the job of a handheld magnet. Magnetic particles in the device respond to the magnet held against the patient’s skin. The device bends slightly and glides along the stomach wall. “The slight bend and how it moves are inspired by a penguin sliding on its belly”, says Venkat Kalpathy Venkiteswaran, corresponding author of the publication.

The device has been tested in animal models. The researchers aim for a diagnostic tool for the clinic. Future versions could detect bleeding or measure temperature. For patients who currently have no alternative to endoscopy, that would be a meaningful change.

About the research

The study is a collaboration between the University of Twente, the University of Groningen, Fudan University, and Hong Kong Baptist University. The paper, Electronics-free soft robotic minitablet for on-demand gastric molecular sensing and diagnostics in vivo, was published in Science Advances.

DOI: 10.1126/sciadv.aea3309