Washington, Nov 27 : In a new research, scientists have demonstrated that the force of light can be harnessed to run nanomachines, which is being considered the first step towards the development of spacecraft powered by the optical force of the sun's light.
The research, led by researchers at the Yale School of Engineering and Applied Science, demonstrates a marriage of two emerging fields of research - nanophotonics and nanomechanics - which makes possible the extreme miniaturization of optics and mechanics on a silicon chip.
Though the energy of light has been harnessed and used in many ways, the "force" of light is different. It is a push or a pull action that causes something to move.
"While the force of light is far too weak for us to feel in everyday life, we have found that it can be harnessed and used at the nanoscale," said team leader Hong Tang, assistant professor at Yale.
"Our work demonstrates the advantage of using nano-objects as "targets" for the force of light - using devices that are a billion-billion times smaller than a space sail, and that match the size of today's typical transistors," he added.
Until now, light has only been used to maneuver single tiny objects with a focused laser beam - a technique called "optical tweezers."
According to postdoctoral scientist and lead author, Mo Li, "Instead of moving particles with light, now we integrate everything on a chip and move a semiconductor device."
"When researchers talk about optical forces, they are generally referring to the radiation pressure light applies in the direction of the flow of light," said Tang. "The new force we have investigated actually kicks out to the side of that light flow," he added.
While this new optical force was predicted by several theories, the proof required state-of-the-art nanophotonics to confine light with ultra-high intensity within nanoscale photonic wires.
The researchers showed that when the concentrated light was guided through a nanoscale mechanical device, significant light force could be generated - enough, in fact, to operate nanoscale machinery on a silicon chip.
The light force was routed in much the same way electronic wires are laid out on today's large scale integrated circuits. Because light intensity is much higher when it is guided at the nanoscale, they were able to exploit the force.
"We calculate that the illumination we harness is a million times stronger than direct sunlight," said Wolfram Pernice, a Humboldt postdoctoral fellow with Tang.
"While this development has brought us a new device concept and a giant step forward in speed, the next developments will be in improving the mechanical aspects of the system," said Tang.