Superconductor Properties Used to Build Motor

Scientists at the Argonne National Laboratory have developed what they say is the world’s first electrical motor based on the properties of new superconducting ceramics.

The unit, called the Meissner motor, operates at 50 revolutions per minute.

“It’s too small for practical use and produces negligible power, but it demonstrates for the first time that these motors are possible,” Roger Poeppel, an Argonne ceramics specialist, said Friday.

“We’re all very excited about it. It has great potential,” he said.

Superconductors are little-understood materials that transmit electricity without energy loss.

Promise of Cheap Power

If the process can be controlled and the right materials developed, superconductivity offers the promise of cheaper electrical power, faster and more efficient electronics and powerful magnets that can be used for everything from levitating high-speed trains to building new atom smashers.

Superconductivity had been known in certain materials, but only when they were cooled to 459.7 degrees below zero Fahrenheit. Achieving that temperature required costly and hard-to-handle liquid helium.

But recent research has produced materials that become superconductors at higher temperatures.

The Meissner motor built at Argonne consists of an 8.5-inch circular aluminum plate with 24 small electromagnets mounted around its circumference.

The plate rotates above two disks of yttrium-barium-copper oxide, a ceramic material that becomes a superconductor at 290 degrees below zero Fahrenheit, Poeppel said.

Based on Meissner Effect

The motor is based on the Meissner effect, a property of superconductors that causes them to expel magnetic fields. When a magnet comes near a superconductor, the superconductor repels it.

“It’s the same repulsion you feel when you push north poles of two magnets together,” Poeppel said. “They want to fly apart.”

The motor’s first public showing will be at the February meeting of the American Assn. for the Advancement of Science in Boston.

Looks to Next Step

“I guess New Year’s Day is a good day for predictions,” Poeppel said. “The next step we’re looking for is a design that would lead to a commercially practical motor, in a cost sense as well as power. I would guess that’s 10 years away.”

Argonne National Laboratory, located west of Chicago, is operated by the University of Chicago for the U.S. Department of Energy.