New Way For Objects To Levitate And Be Driven Only By Light

Eddie Gonzales Jr. – MessageToEagle.com – Using only light, researchers at Caltech found a way to levitate and propel objects. Their work, however, remains theoretical for the time being.

The technology can be used in future to “control the trajectory of ultra-light spacecraft with laser propulsion for space exploration.” A spacecraft (powered and accelerated only by light) could reach the neighboring planet outside of our solar system in 20 years

If the technology can be realized, it means that space vehicles will not need fuel. A powerful laser fired at the probe would be enough to drive in complete.

Conceptual illustration of a nano-patterned object reorienting itself to remain in a beam of light.
Credit: Courtesy of the Atwater laboratory

Decades ago, the development of so-called optical tweezers enabled scientists to move and manipulate tiny objects, like nanoparticles, using the radiative pressure from a sharply focused beam of laser light.

“One can levitate a ping pong ball using a steady stream of air from a hair dryer. But it wouldn’t work if the ping pong ball were too big, or if it were too far away from the hair dryer, and so on,”  Ognjen Ilic, postdoctoral scholar of the the Division of Engineering and Applied Science at Caltech, and the study’s first author, said in a press release.

Not only spacecraft but also many other objects could be manipulated with a light beam, because as researchers write in their paper: “light is a powerful tool to manipulate matter, but sometimes approaches often necessitate focused, high-intensity light of limits the manipulated object’s shape, material and size.

The key is to create specific nanoscale patterns on an object’s surface. This patterning interacts with light in such a way that the object can right itself when perturbed, creating a restoring torque to keep it in the light beam. Thus, rather than requiring highly focused laser beams, the objects’ patterning is designed to “encode” their own stability. The light source can also be millions of miles away.

“We have come up with a method that could levitate macroscopic objects,” said Harry Atwater, Howard Hughes Professor of Applied Physics and Materials Science in Caltech’s Division of Engineering and Applied Science.

“There is an audaciously interesting application to use this technique as a means for propulsion of a new generation of spacecraft. We’re a long way from actually doing that, but we are in the process of testing out the principles.”

Paper

Written by Eddie Gonzales Jr. – MessageToEagle.com Staff Writer