No, it's not the latest fitness craze - although I wouldn't be surprised if this discovery leads us down that path.
Generating enough energy to power devices that monitor our bodies internally, without harming us, is tricky. But MIT researchers have engineered a device that can harvest energy using a chemical reaction-driven battery.
Their device generated an average of 0.23 microwatts for over six days in the gastrointestinal tract of a pig, while continuously measuring the animal's temperature - data the researchers were able to collect wirelessly.
This is a major step forward in ingestible devices, as previously only short, minute-long bursts were possible, they say.
Ingestible electronics have revolutionized the standard of care for a variety of health conditions. Extending the capacity and safety of these devices, and reducing the costs of powering them, could enable broad deployment of prolonged-monitoring systems for patients.
Although previous biocompatible power-harvesting systems for in vivo use have demonstrated short (minute-long) bursts of power from the stomach, little is known about the potential for powering electronics in the longer term and throughout the gastrointestinal tract.
This power-harvesting cell could provide power to the next generation of ingestible electronic devices for prolonged periods of time inside the gastrointestinal tract.