KentuckyFC writes: Superconductors allow current to flow with zero resistance when cooled below some critical temperature. They are the crucial ingredients in everything from high-power magnets and MRI machines to highly sensitive magnetometers and magnetic levitation devices. But one big problem is that superconductors work only at very low temperatures — the highest is around 150 kelvin (-120 degrees centigrade). So scientists would dearly love to find ways of raising this critical temperature. Now a group of physicists say they've found a promising approach: to build metamaterial superconductors that steer electrons in the same way as other metamaterials steer light to create invisibility cloaks. The inspiration for the work comes from the observation that some high temperature superconductors consist of repeated layers of conducting and dielectric structures. So the team mixed tin — a superconductor at 3.7 kelvin — with the dielectric barium titanate and found that it raised the critical temperature by 0.15 kelvin. That's the first demonstration that superconductors can be thought of as metamaterials. With this proof of principle under their belts, the next step is to look for bigger gains at higher temperatures.