A researcher at Stanford University has devised a method of charging devices within a user’s body, paving the way for advanced sensors and implants that would keep themselves charged when worn.

The research, published on Monday in the Proceedings of the National Academy of Sciences, says that smaller, longer-lasting sensors can now be developed, such as pacemakers, nerve stimulators and other implanted medical devices.

At present, most of these devices run on long-lasting big batteries that sometimes require another batch of surgery to replace or recharge.

But with the new approach, using ‘mid-field wireless transfer, doctors could rely on technology rather than drugs to treat some diseases.

Ada Poon, an assistant professor of electrical engineering at Stanford, said: "We need to make these devices as small as possible to more easily implant them deep in the body and create new ways to treat illness and alleviate pain."

Poon headed a research team that developed a pacemaker smaller than a grain of rice that is recharged by holding a small power source above the location of the body which it is implanted in.

Furthering this research, theoretical technology lies waiting for use in bionics, brain chips, and even palm impants.

Wireless charging currently exists for some smartphones, and Google’s upcoming Android Wear watches support this functionality.

The technology uses near-field waves, a type of electromagnetic wave, and the technology is currently being embedded in pigs and rabbits for testing.