Sakhrat Khizroev of Florida International University inserted 20 billion of these nanoparticles into the brains of mice. He then switched on a magnetic field, aiming it at the clump of nanoparticles to induce an electric field. An electroencephalogram showed that the region surrounded by nanoparticles lit up, stimulated by this electric field that had been generated.
In the long term his nanoparticle system may offer a new way to interact with computers. He hasn’t tried it yet, but he says running it in reverse, so that the nanoparticles produce a measurable magnetic field in response to the brain’s own electrical fields, is possible. Our brain states would become input parameters for computers, which would be able to directly stimulate specific regions of the brain in return.
For now, though, the promise is in understanding and treating our brains without the side effects of implants and optoelectronics.