Researchers have been plugging away at ingestible devices that collect data, deliver drugs, and monitor health inside the body. These devices need power. But conventional batteries are rigid, take up space, and can injure or obstruct the GI tract.
For a more palatable power source, researchers made a swallowable battery from a rice paper–like material and body-compatible elements (Nat. Chem. Eng. 2026, DOI: 10.1038/s44286-026-00443-7). The edible battery powered small electronics devices in pig stomachs for 3 days and then broke down.
Cooking up edible devices that work reliably in the body and then safely degrade is not easy. The challenge is finding benign high-performance materials that can handle the gastrointestinal tract’s harsh acidic environment and squeezing forces. Researchers have often used materials found in foodstuffs to make resorbable electronics. Some have made biocompatible batteries that run on bodily elements, such as the body’s oxygen as an energy source or gastric fluid as the electrolyte.
Giovanni Traverso, a mechanical engineer at the Massachusetts Institute of Technology, says his team’s goal was to make a battery that is biocompatible and biodegradable. They were inspired by the thin, edible rice paper that is used to wrap some Asian candies.
The team made a papery cathode from cellulose nanofibers, molybdenum trioxide, and activated carbon; a magnesium alloy served as the anode. Between the electrodes, the researchers sandwiched a biodegradable ionic liquid electrolyte that they made by melting choline chloride and lactic acid. They encapsulated the batteries in beeswax to help them survive in the body.
To test the batteries, the researchers used an endoscope to deliver them into pig stomachs. The batteries powered two devices: a radio-frequency identification (RFID) tag that transmitted signals to a detector outside the body, and an electrical stimulation device that triggered the release of a hunger hormone. The RFID tag was made of a molybdenum antenna on a nondegradable chip.
Traverso and his colleagues retrieved the batteries after 24 h and 72 h to measure output and used endoscopic and X-ray imaging to monitor degradation. The battery worked for 3 days, over which the voltage dipped from 1.84 V—slightly more than a standard AA battery—to 1.45 V.
Images showed that the molybdenum antenna and battery disintegrated into tiny fragments within a few weeks. The tiny nonresorbable RFID chip was excreted naturally, and the entire device degraded within a few months.
Adjusting the thickness of the layers and the encapsulation materials would make the batteries last longer in the body, Traverso says. “They’re readily tunable to the application. Depending on the design, they could be made functional for days to weeks.”
Longer-lasting batteries could power implants that simulate neurons, trigger hormone release, or release pain medications, he says. “Systems like this could also be used to make environmental sensors that eventually degrade.”
Yasser Khan, an electrical and computer engineer at the University of Southern California who was not involved in the study, says that “powering electronics that go inside the body is one of the biggest challenges in our field.” Today’s batteries contain harmful materials and have to be removed once they run down. The new battery “is an important step toward swallowable devices that can monitor or treat the gut and then disappear,” Khan says.
Before it can be used in people, the ingestible battery will need extensive biocompatibility testing, he says. “We need to know exactly what the battery breaks down into, how much of it the body absorbs, and whether any of it irritates or harms the gut, especially if patients swallow these devices again and again.”
