Invisibility once belonged squarely in the realm of science fiction but in the last few years advancements in metamaterials have made it an exciting possibility, though not yet in the range of normal human vision or on a cost-effective basis.

Scientists in the Departments of Applied Physics and Electromagnetism at the University of Granada have taken a different tack, using the Transmission Line Method(TLM).

In 1885, Oliver Heaviside created the first transmission line model to understand the behavior of wires in the telegraph. That's right, pre-telephone Morse Code stuff. Future tech like invisibility can learn a thing or two from James Clerk Maxwell even today, it seems.

Professors Jorge Andrés Portí, Alfonso Salinas and Juan Antonio Morente say they can use TLM to hide an object or make it invisible, at a certain frequency, inside an electromagnetic simulator.

It's part of the doctoral thesis carried out by Cedric Blanchard and done in collaboration with the Massachusetts Institute of Technology (MIT) and they recently published data in Optics Express.

The researchers have proposed a TLM simulation of hiding structures, composed of alternating isotropic layers, imitating an anisotropic frame. They had previously implemented a new technique to simulate meta-materials with the TLM method.

"This new prospect leaves the usual TLM process virtually untouched; specifically, the delivery matrix is exactly the same used in classic environments, which provides a lot of flexibility when it comes to program," they say.

This will make it possible to improve the effectiveness of hiding if the electromagnetic parameters of the frame are judiciously chosen.