Washington: Engineers have developed a tiny, wirelessly powered, self-propelled device that can navigate the blood stream to deliver drugs, do diagnostics or microsurgeries.

Ada Poon, assistant professor at the Stanford School of Engineering, demonstrated the device Wednesday at the International Solid-State Circuits Conference (ISSCC) in the US.

"Such devices could revolutionize medical technology," said Poon. "Applications include everything from diagnostics to minimally invasive surgeries."

Poon is developing a new class of medical devices that can be implanted or injected into the human body and powered wirelessly using electromagnetic radio waves. No batteries to wear out. No cables to provide power.

Certain of these new devices, like heart probes, chemical and pressure sensors, cochlear implants, pacemakers, and drug pumps, would be stationary within the body, according to a Stanford statement.

Others, like Poon's most recent creations, could travel through the bloodstream to deliver drugs, perform analyses, and perhaps even zap blood clots or removing plaque from sclerotic arteries.

"While we have gotten very good at shrinking electronic and mechanical components of implants, energy storage has lagged in the move to miniaturize," said co-author Teresa Meng, professor of electrical engineering and of computer science at Stanford.

"This hinders us in where we can place implants within the body, but also creates the risk of corrosion or broken wires, not to mention replacing ageing batteries," Meng said.

Poon's devices are different. They consist of a radio transmitter outside the body sending signals to an independent device inside the body that picks up the signal with an antenna of coiled wire.