Colloquium

Transformation design and metamaterials: tools for conceiving and realizing unique devices

David Schurig
Duke University
Wednesday, February 13, 2008
Higgins 310, 4 pm

Transformation design is a method for finding a set of material properties that implement the same field behavior as a topological distortion or "space warp". Many (i.e. all linear, non-lossy, non-dispersive) material specifications have a corresponding coordinate transformation, which describes the equivalent space warp. In some cases, such as for an invisibility cloak, it is much easier to conceive of the desired space warp, and use the tools of differential topology to calculate the corresponding material specification, than it would be to find it by other means.

In addition to the infamous cloaking device, this method has been used to design field concentrators and near-field magnifiers (i.e. hyper-lenses), and has been applied to both electromagnetic and acoustic fields.

On the down side, the method usually results in challenging material specifications that are both inhomogeneous and anisotropic. Fortunately, metamaterial comes to the rescue with its ability to implement just such specifications.

I will discuss the mathematical foundations of the transformation design method, some illustrative and useful examples, and the joys, difficulties and limitations of implementing the resulting specifications using metamaterials.