ARGONNE, ILL., JAN. 1 -- Scientists at 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 today.
"We're all very excited about it. It has great potential," he said.
Superconductors are little-understood materials that transmit electricity without energy loss.
If the process can be controlled and the proper materials developed, superconductivity offers the promise of cheaper electrical power, faster and more efficient electronics and powerful magnets that can be used for purposes ranging 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.
Argonne's Meissner motor 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.
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."
He said the motor was not designed to work better than a traditional engine but to demonstrate that superconducting properties of material could be used in building a motor.
When the material is cooled with liquid nitrogen below the critical point to make it superconducting, the motor begins to run, Poeppel said. When the liquid nitrogen evaporates and the material warms above the critical temperature, the motor stops, he 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," Poeppel said. "I would guess that's 10 years away."