Enlarge / A small, ingestible voltaic cell powered by the acidic fluids in the stomach. (credit: MIT | Diemut Strebe)

New wireless gadgets could deliver drugs and continuously measure temperature, all while harvesting energy from churning, acidic gut fluids, researchers report this week in Nature Biomedical Engineering. Prototypes have successfully made their way through the bowels of pigs, and the design will need tweaking for human use. But the findings suggest that next-generation ingestible devices will be able to safely harvest energy for a slew of health tracking and monitoring purposes—potentially even for extended periods of time.

Consumable contraptions have already proved useful for video capture and health monitoring. They measure things like breathing, temperature, pH, drug delivery, heart rate, and pressure. But most gulp-able gadgets still require an old-fashioned battery, which can cause life-threatening burns and injuries in living tissue.