Robot limbs to plug into the brain with light - tech - 17 October 2010 - New Scientist

Robot limbs to plug into the brain with light: The sensors are based on spherical shells of a polymer that changes shape in an electric field. The shells are coupled with an optical fibre, which sends a beam of light travelling around inside them.

The way that the light travels around the inside of the sphere is called a "whispering gallery mode", named after the Whispering Gallery in St Paul's Cathedral, London, where sound travels further than usual because it reflects along a concave wall.

The idea is that the electric field associated with a nerve impulse could affect the shape of the sphere, which will in turn change the resonance of the light on the inside of the shell; the nerve effectively becomes part of a photonic circuit. In theory, the change in resonance of the light travelling through the optical fibre could tell a robotic arm that the brain wants to move a finger, for instance.