Ingestible paper battery developed: Dissolves in the digestive system after completing its task

Scientists have developed an ingestible, gradually dissolving, paper-like battery to provide energy for medical devices used temporarily in the stomach and intestines. In initial experiments conducted on pigs, the system was reported to function stably for up to three days.

The study, published in the journal Nature Chemical Engineering, tested two different battery models. The smaller model was designed to fit inside a standard gelatin capsule. The second model, which has a higher capacity, was prepared for applications requiring more energy.

In the experiments, the small battery powered a wireless identification tag placed in the esophagus that detects when medication is swallowed. The larger model was used to operate an ingestible capsule that electrically stimulates the stomach and increases the level of hunger hormones in the blood.

BATTERY OPERATING TIME IS ADJUSTED WITH COATING

Batteries used in traditional ingestible devices must be heavily insulated to prevent harmful substances from leaking out. This increases the size of the battery and can complicate the design of temporary medical devices. In the new battery, materials that the body can tolerate and that dissolve over time were chosen.

The structure developed by the researchers includes a magnesium alloy at the anode, and molybdenum trioxide and activated carbon at the cathode. Cellulose nanofibrils form the battery's thin, porous, and paper-like skeleton.

To prevent the battery from breaking down as soon as it reaches stomach acid, a coating consisting of beeswax and candelilla wax was used on the outer surface. This coating allows the battery to produce energy for a certain period while subsequently allowing for gradual dissolution within the digestive system.

The study noted that the battery and its biodegradable components could disappear completely over time. However, the electronic circuit board used in the stomach stimulation experiment does not yet possess the same property; this part was excreted from the pigs' digestive systems through natural means.

The research team believes that making all parts of the device absorbable by the body could reduce the risk of blockages caused by residues in the intestines. The next phase aims to improve production standards and make the battery's operating time more predictable through coating thickness.

For now, the technology has only been tested on pigs. Researchers aim to move to human clinical trials within approximately two years. If shown to be safe and effective in humans, it could contribute to the use of temporary gastrointestinal devices without the need for surgical intervention.