SRI International Receives Patent for Frictionless Transport Technology Based on Diamagnetic Levitation

System Provides Stable, Frictionless Transport for Use in Ultra-Clean Manufacturing

MENLO PARK, Calif., December 5, 2002 - SRI International, a leading independent research institute, today announced that the United States Patent and Trademark Office has issued SRI a patent for its frictionless transport technology based on diamagnetic levitation (U.S. Patent No. 6,483,222). SRI has now patented both the linear (point-to-point) and rotational uses of this technology.

This levitated, frictionless transport technology has been built into a pilot production line by a commercial client, and represents the known record for the heaviest mass suspended using diamagnetic levitation: 22 lbs (10 kg). SRI's work in this field earned SRI two "Best of Show" awards at the Sensors and Motion Control Exposition held in Anaheim, California, in May 2000.

The inventors are Dr. Ronald E. Pelrine and Dr. Jonathan R. Heim of SRI International.

Frictionless Transport Key to Next Generation of Clean Manufacturing
Since modern electronics and chemical compounds are manufactured within ever-tighter tolerances and purity requirements, the need to maintain a clean manufacturing environment becomes progressively more acute. Companies must consider not only the amount of potentially contaminating particles that are brought into a manufacturing facility, but also the amount generated by the facility itself.

The gears, pulleys, and other mechanical devices that ferry materials between stages in the manufacturing process constantly rub against each other during operation. This friction casts off particles that could contaminate products during the manufacture process and greatly reduce overall yield.

SRI's diamagnetic levitation offers a friction-free solution to this problem. Unlike conventional magnetic bearings, SRI's patents cover the use of the passive magnetism supplied by permanent magnets stabilized with diamagnetic materials, thereby requiring no additional power to provide lift. SRI's claims on both the linear and rotational uses of this technology cover a wide-range of areas in common manufacturing practice where traditional mechanics can be replaced by friction-free, levitation-based counterparts. The technology is designed for a broad range of high and low temperatures, including room temperature and above.

SRI's expertise in harnessing the useful aspects of diamagnetism-a weak, repelling magnetic force exhibited by many materials that are commonly thought not to have magnetic properties-provides the necessary stability for this system. Until recently, the diamagnetic phenomenon represented little more than a laboratory curiosity. SRI's patent and its application prove that diamagnetic levitation has strong potential for industry. The technology is available for licensing.

More information about SRI's work in advancing the science behind diamagnetic levitation can be located at http://www.sri.com/esd/automation/diamagnetic.html.

About SRI International
Silicon Valley-based SRI International (http://www.sri.com) is one of the world's leading independent research and technology development organizations. Founded as Stanford Research Institute in 1946, SRI has been meeting the strategic needs of clients for more than 55 years. The nonprofit research institute performs contract research and development for government agencies, commercial businesses and private foundations. SRI is well known for its innovations in information technology, telecommunications, engineering, pharmaceuticals, chemistry, physics, and the public policy areas of education, health, and economic development. In addition to conducting contract R&D, SRI licenses its technologies, forms strategic partnerships and creates spin-off companies.