New metamaterial lens focuses radio waves

New metamaterial lens focuses radio waves: The concave lens exhibits a property called negative refraction...


Prior to this recent paper, Wu and others have studied how certain shapes of metamaterials can affect the propagation of electromagnetic waves. The team came up with a blocky, S-shaped “unit cell” whose shape refracts radio waves in particular directions. Ehrenberg used the unit shape as the basis for his concave lens, creating the rough shape from more than 4,000 unit cells, each only a few millimeters wide.

To fabricate his design, Ehrenberg utilized 3-D printing, building a lens layer by intricate layer from a polymer solution. He then washed away any residue with a high-pressure water jet and coated each layer with a fine mist of copper to give the lens a conductive surface...

The device, which weighs less than a pound, may be used to focus radio waves precisely on molecules to create high-resolution images — images that are currently produced using bulky, heavy and expensive lenses. Ehrenberg says that such a lightweight device could also be mounted on satellites to image stars and other celestial bodies in space, “where you don’t want to bring up a hefty lens.”