Organic Chemists Contributing to New Discoveries: Metamaterials

Background - Why is this important?

Metamaterials are artificial structures with all sorts of unusual and useful functionalities like the ability to bend light or sound in an unnatural way. 

They typically consist of carefully defined arrangements of metal resonators engineered to interact or control electromagnetic waves such as visible light and microwaves. Chemists can engineer these properties by subtle manipulation of the atoms and molecules within the structure. In metamaterials the desired properties are achieved by the precise geometrical arrangement of the components resulting in electromagnetic properties that would be otherwise impossible to achieve. 

What could organic chemists do?

The first practical demonstration of such a ‘cloaking’ material operated over a band of microwave frequencies.¹ Whilst development in this area is undoubtedly challenging, the ability of organic chemistry to generate flexible materials and accurately control nano-environments, as has been so elegantly demonstrated in the development of plastic electronics in the last twenty years,^2,3 suggests that collaborations between physicists and organic chemists may well lead to exciting new developments in flexible metamaterials. 

The first truly flexible version of the typically hard and stiff metamaterials used has now been made.⁴  The manufacture of this new material relies on embedding gold patterns into a commercially available organic polymer.  Development of custom-made polymers to support metal resonators should accelerate the development of this area in the future.

What is the predicted impact?

One possible application of metamaterials is that of electromagnetic cloaking, in which a material is used to render a volume effectively invisible to incident radiation.  This has been popularized as the breakthrough science required for an ‘invisibility cloak’, an article of clothing used to great effect by the young wizard Harry Potter. The potential applications of materials that can be used to make objects appear or disappear are left to the reader’s imagination.

References

1  D Schurig, J J Mock, B J Justice, S A Cummer, J B Pendry, A F Starr, D R Smith Science, 2006, 314, 977
2 J H Burroughes, D D C Bradley, A R Brown, R N Marks, K Mackay, R H Friend, P L Burns, A B Holmes Nature, 1990, 347, 539
3  A C Grimsdale, K L Chan, R E Martin, P.G. Jokisz, A.B. Holmes Chem. Rev., 2009, 109, 897 
4  A Di Falco, M Ploschner, T F Krauss New J. of Phys., 2010, 12, 113006