Scientists have developed a small ingestible voltaic cell, equipped with a Wi-Fi transmitter, can harvest energy from inside a patient’s own stomach to record core body temperature and then beam the information to an external monitor.
The prototype can power itself for nearly a week– much longer than current ingestible devices, which are only able to share health data for less than an hour. Indeed, this ingestible device carries the longest-lasting, most potent energy harvester to date.
The voltaic cell recalls an experiment you might have tried in high school: the lemon battery, where citric acid carries a weak electric current between two electrodes.
In the researchers’ version of this, the ingestible is a relatively large cylindrical capsule, measuring about 40 millimetres long and 12 millimetres in diameter (1.6 inches by 0.5 inches), with zinc and copper electrodes attached to the surface of the device.
At that size, the prototype would be too large for human consumption. The researchers say it will be possible to scale the device down in the future to one-third its current size – so that people can swallow it – but at present the prototype has only been tested on pigs.