Ingestible paper battery dissolves after powering gut implants in animal tests
Researchers have developed a swallowable battery made from paper-like materials that can supply electricity to medical devices inside the digestive tract. In pig experiments, the battery kept devices running for up to three days before breaking down into harmless components. The design could eliminate the need for surgical removal of power sources in future human applications.
The battery's layered design pairs a magnesium alloy anode with a cathode of molybdenum trioxide and activated carbon, separated by a biodegradable electrolyte. Cellulose nanofibrils bind these materials into a thin, porous paper-like structure offering better strength and more controlled degradation than earlier prototypes. A beeswax coating shields the battery from stomach acid, with some versions adding candelilla wax for extended protection.
MIT's Giovanni Traverso and colleagues tested the battery in pigs, where it sustained power for up to three days before dissolving into harmless components. This contrasts with conventional ingestible-device batteries, which must remain sealed to prevent toxic leakage and typically require surgical retrieval once depleted. Potential applications include devices that detect internal bleeding, deliver medication, or stimulate specific tissues.
This battery could substantially ease the experience of patients needing temporary gastrointestinal monitoring or treatment. Ingestible devices with conventional batteries often require surgical removal, adding risk and recovery time; a dissolving power source may eliminate that step entirely. Patients with digestive disorders, bleeding conditions, or those requiring targeted drug delivery could benefit most. However, the three-day power window and degradation behavior in human digestive systems remain unverified, so clinical adoption would depend on extensive safety testing before any real-world use becomes feasible.