Materials scientists have been puzzling over how to make metamaterials cheaply and easily. Metamaterials consist of repeating patterns of elements that interact with an electromagnetic wave so as to control and distort its path
At millimetre and microwave wavelengths, these elements are things like wires and c-shaped pieces of metal called split-ring resonators. To make them into metamaterials, they have to be assembled into arrays with vital statistics of the order of the light they are intended to interact with.
Belgium researchers took a handful of polystyrene balls just a few hundred nanometres in diameter and spread them onto a flat gold surface where they naturally self assemble into a hexagonal array with few, if any, defects.
This array then serves as a template for the metamerial. Using a series of steps in which the surface is covered in masks and then etched, the team create a thin slab consisting of a gold-silicon oxide-gold sandwich. However, this slab is punctured by a hexagonal array of holes that correspond to the position of the polystyrene beads.
This is clever, cheap, quick and could be easily scaled