A new technology makes it possible to make use of natural stomach acids to power up ingestible health trackers to monitor the body temperature and other body functions from the inside. Although the device is currently being used on pigs, it could potentially be useful to humans as well.

The small ingestible voltaic cell can be swallowed safely and will operate on the gastrointestinal tract. The cell can be used to power up sensors that will monitor vital signs such as respiration and heart rate. It can also be potentially used for devices that will deliver medicines internally.

The principle behind the powering of the voltaic cell is similar to the lemon's ability to release a weak electric current. The citric acid present on the lemon carries such current between two electrodes. As for the capsule, it has zinc and copper electrodes attached on the device's surface, according to Science Alert.

The current size of ingestible health tracker is a bit larger than what a normal person could swallow (1.6 inches by 0.5 inches). The initial tests conducted on pigs have provided excellent results. The zinc acts as an anode, which releases ions whenever it touches gastric acid. Then it acts as an electrolyte, which will then carry an electric current to the copper cathode.

The cells generate 0.1 to 0.2 volts of power, but by using a capacitor, it can be increased to 2.2 to 3.3 volts. The power is similar to a small alkaline battery. The voltage is enough to be used on different kinds of sensors. It was also enough to transmit updates of data to a nearby device every 12 seconds.

Electrical engineer Phillip Nadeau said, "We can get relatively consistent power, enough to power temperature measurements on a minute by minute basis and transmit wirelessly," The Scientist reported.

The technology will be further developed to be easily swallowed by humans. Safety concerns will also be considered to avoid any potential toxicity dangers.