Metamaterials could lead to better large-area absorbers

Metamaterials are man-made materials that have properties often absent in natural materials and are constructed to provide control over the properties of waves, such as light. Creating these materials for visible light is still a technological challenge that has traditionally been achieved by lithography, in which metallic patterns are etched onto an inert material, much like an inkjet printer.

As effective as lithography has been in creating such structures, it does have a limitation in that it is very expensive and difficult to scale up to the large surface areas required for many applications.

In a statement, Cristian Ciracì, a research scientist at Duke’s Pratt School of Engineering, said: ‘Our new approach is more of a bottom-up process. It may allow us to create devices — such as efficient solar panels — that cover much larger areas. In our experiments, we demonstrated an extraordinarily simple method to achieve this.’

The results of Ciracì and co-workers’ experiments, which were conducted in the laboratory of senior researcher David R Smith, William Bevan professor of electrical and computer engineering at Duke, were published on 6 December in the journal Nature.