Superconductors

New research is unlocking the amazing potential of high-temperature superconductors.

Few technologies ever enjoy the sort of rock-star celebrity that superconductors received in the late 1980s.

Headlines the world over trumpeted the discovery of "high temperature" superconductors (abbreviated HTS), and the media and scientists alike gushed over the marvels that we could soon expect from this promising young technology. Levitating 300-mph trains, ultra-fast computers, and cheaper, cleaner electricity were to be just the beginning of its long and illustrious career.

Today we might ask, like a Hollywood gossip columnist: what ever happened to the "high-temp" hype?

"It was the hottest potato of its time, but it all fizzled out," says Louis Castellani, president of the Houston-based HTS company Metal Oxide Technologies, Inc. (MetOx).

The problem was learning to make wire out of it. These superconductors are made of ceramics - the same kind of material in coffee mugs. Ceramics are hard and brittle. Finding an industrial way to make long, flexible wires out of them was going to be difficult.

Indeed, the first attempts were disappointing. So-called "first generation" HTS wire was relatively expensive: 5 to 10 times the cost of copper wire. Furthermore, the amount of current it could carry often fell far short of its potential: only 2 or 3 times that of copper, versus a potential of more than 100 times.

Image courtesy MetOx "Second generation" HTS wire can carry the same amount of current as copper wire hundreds of times as thick.

But now, thanks to years of research involving experiments flown on the space shuttle, this is about to change.

The NASA-funded Texas Centre for Superconductivity and Advanced Materials (TcSAM) at the University of Houston is teaming with MetOx to produce the "smash hit" that scientists have been seeking since the '80s: a "second generation" HTS wire that realizes the full 100-fold improvement in current capacity over copper yet costs about the same as copper to produce.