Scientists made a paper battery you can swallow to power internal medical devices

Scientists have created a swallowable paper battery capable of powering internal medical devices and gradually dissolving after its task is complete. The battery was tested on pigs, where it sustained devices for up to three days. If successful in humans, it could power temporary devices inside the gut, eliminating the need for surgical battery retrieval.

Reza Ghodssi, a professor of electrical and computer engineering at the University of Maryland, expressed excitement about the battery's potential to reduce the size of ingestible devices. The battery operates by dissolving in the acidic gastrointestinal tract, with an anode made of magnesium alloy and a cathode containing molybdenum trioxide and activated carbon.

A biodegradable electrolyte and a paper-like structure made of cellulose nanofibrils bind the layers. To prevent excessive breakdown in stomach acid, the battery is coated with beeswax and candelilla wax. The researchers tested two battery sizes, with one capable of powering low-power electronics and the other suitable for slightly more demanding devices.

In pig tests, both battery versions operated for up to three days. The battery was used to power a wireless RFID tag and a stomach-stimulation capsule, both in pigs. The battery and its components gradually degraded, but the electronic circuit board did not, indicating its eventual natural breakdown. The main challenge now is improving the battery's capacity and ensuring all parts are biodegradable to prevent any leftover components from causing harm.