Superconducting Motors: Getting Warmer
Ever since their discovery five years ago, high-temperature superconductors--ceramic oxides that can carry electricity with no resistance at minus 328F--have presented researchers with formidable barriers to commercialization. One huge hurdle has been getting superconducting wires to carry the large currents necessary in the workaday world.
In August, these materials took another step closer to the marketplace. CPS Superconductor Corp., a Milford (Mass.) subsidiary of Ceramics Process Systems Corp., announced that its proprietary "melt recrystallization" process is producing wire with "critical current densities" in excess of 100,000 amperes per square centimeter. When coupled with the fact that the wire can still carry nearly half that current in a magnetic field, the materials should be suitable for use in superconducting motors--one of the most important applications. In fact, CPS and Emerson Electric Co. have jointly developed a prototype of a superconducting motor under a grant from the federal Defense Advanced Research Projects Agency. While that's an important step, no one is hinting that a commercial technology is around the corner just yet.