A biobattery that is safe to swallow and power ingestible cameras will advance medical assessments of the small intestine.

The device engineered at the State University of New York at Binghamton is composed of microbial fuel cells with dormant spore-forming Bacillus subtilis bacteria that remain inert until arriving at the small intestine. A pH sensitive membrane prevents power production until this biological destination is reached. As nutrient-rich intestinal fluid enters the biobattery at the target site, the bacteria begin to feed and generate small amounts of electricity in the process.

A new biobattery could power ingestible cameras in the small intestine. Source: State University of New York at Binghamton

When submerged in simulated intestinal fluid, the biobattery produced a current density of 470 µA/cm² and a power density of 98 µW/cm², suggesting that it has potential to energize ingestible devices. With additional improvements, the technology may provide an alternative to conventional batteries that are short-lived or pose a health risk if they began to leak or became damaged in the body.

The researchers next seek to enhance the performance of the microbial fuel cell system described in Advanced Energy Materials by accelerating its activation time — currently an hour — upon reaching the small intestine. The power density produced is sufficient for wireless transmission, but a greater output would expand its utility for drug delivery and other ingestible healthcare technologies.