A metamaterial power harvester

Metamaterials are composite materials whose electromagnetic or acoustic properties are quite different from those of the subwavelength building blocks they comprise. By careful tailoring of small constituent pieces, researchers can create large-scale exotic phenomena such as negative indices of refraction, superlensing, and invisibility cloaking (see the articles by John Pendry and David Smith, Physics Today, June 2004, page 37, and by Martin Wegener and Stefan Linden, Physics Today, October 2010, page 32). Metamaterials have also shown promise for more familiar applications, including harmonic generation and nonlinear wave mixing. Allen Hawkes, Alex Katko, and Steve Cummer at Duke University have now demonstrated that metamaterials can function well as power harvesters, rectifying incident RF energy to deliver DC power to integrated components.