The new concept of ‘digital metamaterials’, a simplified way of producing metamaterials with many different properties, is described online this week in Nature Materials. Metamaterials are artificially made composites that can interact with light, sound and with waves more generally in unconventional ways, resulting in behaviour that is not found in nature.
How metamaterials behave is determined by the properties of their constituent subunits and how they are arranged. Metamaterials are currently used in the development of invisibility cloaks and hyperlenses, that is, lenses that are not subject to the inherent limitations of conventional lenses.
Nader Engheta and Cristian Della Giovampaola propose using just two subunits - or ‘metamaterial bits’ - that have opposing properties, similar to the use of 1’s and 0’s in binary code. They then use computer simulations to create layered structures constituting ‘metamaterial bytes’ of increased functionality and complexity. These simulations, which use various shapes and arrangements, are shown to replicate the many exotic properties found in existing, more complex metamaterials. The authors demonstrate that this method can be used for lensing and hyperlensing applications, as well as to achieve properties such as transparency and cloaking.