Researchers at MIT have used 3D printing to fabricate a three-dimensional, lightweight metamaterial lens that focuses radio waves with extreme precision.
Essentially this is tech geek heaven. Metamaterials are manmade, with intricately designed structures that are capable of bending electromagnetic waves in ways that are impossible for materials found in nature. Possible future applications for this lens in particular and metamaterials in general sound much like science fiction. MIT reports that ‘scientists are investigating metamaterials for their potential to engineer invisibility cloaks — materials that refract light to hide an object in plain sight — and “super lenses,” which focus light beyond the range of optical microscopes to image objects at nanoscale detail.’
However, a small group of researchers at MIT have now developed and produced a 3D printed, lightweight metamaterial lens that focuses radio waves with extreme precision. The concave lens exhibits a property called negative refraction, bending electromagnetic waves — in this case, radio waves — in exactly the opposite sense from which a normal concave lens would work.
Isaac Ehrenberg, an MIT graduate student in mechanical engineering has been working on the device and his way of explaining it will get many excited because for him it ‘evokes an image from the movie “Star Wars”: the Death Star, a space station that shoots laser beams from a concave dish, the lasers converging to a point to destroy nearby planets.’ This is not the application for which this lens has been developed, obviously, but Ehrenberg says there are other potential applications for the device, such as molecular and deep-space imaging.
The complex structure of the lens was produced by 3D printing a polymer, cleaning the surface and then coating it with a fine mist of copper to make the lens conductive.
The lens was tested by placing it between two radio antennae and measuring the energy transmitted through it, whereby it was found that most of the energy was able to travel through the lens, with very little lost within the metamaterial — a significant improvement in energy efficiency when compared with past negative-refraction designs. The team also found that radio waves converged in front of the lens at a very specific point, creating a tight, focused beam.
These results are a huge step forward in proof of concept for such a light structure with the next challenge being the ability to scale it up for potential applications that include creating super high-resolution images — images that are currently produced using bulky, heavy and expensive lenses. Other applications include mounting such a lightweight device on satellites to image stars and other celestial bodies in space and stronger, faster telecommunications.
And as Ehrenberg says: “You can really fully explore the space of metamaterials. There’s a whole other dimension that now people will be able to look into.”