Caltech researchers have devised an ingenious way to both levitate and set in motion different objects using nothing more than light, and arrived at this discovery after figuring out a way to create the perfect nanoscale patterning just along the surfaces of these objects.
According to Phys.org, it is important to note that this work is still purely theoretical. However, this important research could set in motion the construction of a spacecraft which would move so swiftly that it may, in the future, take as little as 20 years to travel to the closest planet just outside the edge of our solar system, all of which would be accomplished through the use of light.
The latest research centered upon nanoscale patterning and levitation of objects through light was undertaken in the laboratory of Harry Atwater at Caltech’s Division of Engineering and Applied Science.
While the movement of objects through light has been accomplished before, it was certainly not on this scale. For instance, optical tweezers were created decades ago, and this creation helped scientists to shuffle around minuscule objects, including nanoparticles, using nothing more than laser light.
Unfortunately, as amazing as optical tweezers may be, they are only able to move small objects and certainly would not be able to propel spacecraft out of our solar system, or indeed, anywhere.
Optical tweezers can already move nanoparticles using light – now Caltech scientists have designed a way to use light to levitate and accelerate larger objects by creating specific nanoscale patterning on the objects' surfaces. https://t.co/2PR9rjmm19 pic.twitter.com/30SDdcKUCk
— Caltech (@Caltech) March 18, 2019
As Ognjen Ilic, the study’s first author, summarized the Caltech discovery that light can be used in conjunction with nanoscale patterning to levitate objects, “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.”
Thanks to this new study, researchers believe that a light beam can now be used to move a wide range of different sized objects ranging from micrometers all the way to meters, as long as the perfect nanoscale patterning is created on the surface of these objects. This patterning is also extremely useful as researchers won’t need to use a standard focused laser beam on the objects, but will instead be able to rely upon the patterning of these objects to “encode” the perfect movement.
There is also the added benefit that with the proper nanoscale patterning, a light source can be focused on these objects from a great distance away, which would be extraordinarily helpful in the case of spacecraft.
As Atwater noted, while the use of light to levitate objects is still in its infant stages and won’t be used to propel spacecraft out of our solar system tomorrow, with enough planning and work this could certainly happen in the future.
“We have come up with a method that could levitate macroscopic objects. 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.”
The new Caltech study which has demonstrated that nanoscale patterning can be used with light to propel and levitate objects has been published in Nature Photonics.