Doris Kuhlmann-Wilsdorf named Inventor of the Year

Matthew Bednar

Doris Kuhlmann-Wilsdorf, recently honored by the U.Va. Patent Foundation, has spent 20 years working on electrical conductivity over sliding surfaces. She has designed new electrical fiber brushes critical to most motors and generators, an example of which is the ring of brushes she is holding here.

By Charlotte Crystal

Doris Kuhlmann-Wilsdorf, who’s been teaching physics and materials science for more than 40 years, has been named Christopher J. Henderson 2001
Inventor of the Year for her improvements to industrial machinery.

The U.Va. Patent Foundation is recognizing her research and six patented inventions relating to electrical brushes, simple but critically important parts of most motors and generators. They establish the electrical connection between an outside power source and the rotating part of machinery, electrically linking moving and stationary objects, such as an electric train and an overhead electrical cable.

Kuhlmann-Wilsdorf, a U.Va. faculty member since 1963, teaches in the physics department and in the Engineering School’s materials science department at U.Va.
“The creative work of Doris Kuhlmann-Wilsdorf and her collaborators is an inspiration to those who believe their ideas can change the world,” said Haydn N.G. Wadley, president and chief executive officer of the U.Va. Patent Foundation.

Doris battled for many years with those who thought they knew better, but has convincinsgly demonstrated the originality and utility of her approach for electric motors. This new technology, using hair-fine metal fiber brushes, promises to transform the capabilities of electric motors and may lead to a host of new applications, from small actuators that can power mobile robots to electric systems that can drive large ships.”

Kuhlmann-Wilsdorf’s patents build on nearly two decades of research on the physics and materials science of electrical-current conduction across sliding surfaces, and a search for how best to make electrical connections between moving and static objects. Although an important topic for industry, it has received little scientific attention.

Despite serious drawbacks, industry has depended almost universally on brushes made of graphite and metal-graphite composites since electric motors and generators were developed in the late 19th century. These brushes create a fine dust, which accumulates in machinery and damages it — a particularly vexing problem in U.S. Navy submarine engines. Graphite brushes also wear out quickly, generate too much friction and electrical heat and fail to generate power as efficiently as they should, Kuhlmann-Wilsdorf said.

Kuhlmann-Wilsdorf’s inventions are poised to eliminate these problems by replacing carbon brushes with “multi-contact” brushes made of various metals and alloys drawn into hair-fine fibers. Replacement is already feasible in a variety of applications, and Kuhlmann-Wilsdorf and her team of researchers continue to pursue a broad array of potential uses.

Kuhlmann-Wilsdorf’s many professional honors include selection as a fellow of the American Physical Society, a fellow of the American Society for Metals International, a member of the National Academy of Engineering and a life member of the American Society for Metals International. Kuhlmann-Wilsdorf also received the 1989 Achievement Award from the American Society of Women Engineers and the Ragnar Holm Scientific Achievement Award from the Institute of Electrical and Electronic Engineers in 1991.

A native of Germany, she received her bachelor’s, master’s and doctoral degrees from Gottigen University. Her publication list of nearly 300 technical articles begins in 1947 and runs through the present.

“Doris is a true creative genius and a delightful person,” said Robert S. MacWright, U.Va. Patent Foundation executive director. “Her ingenuity and love of science are integral parts of her personality, which is flavored with passion and charm.”

The U.Va. Patent Foundation award recognizes an invention of notable value to society. Criteria for selection include commercial success (or potential) and the invention’s value in treating disease, protecting the environment, as a tool for research, in education and training, in the development of a field of science or technology or in helping the disadvantaged, the disabled and the elderly.

The Patent Foundation named the Inventor of the Year Award after Christopher J. Henderson, president and chief financial officer of Robbins & Henderson, a New York firm specializing in financial and related services for institutions, in recognition of Henderson’s interest in technology transfer and commitment to the University. Established in 1992, the award program was conceived by Dr. Richard Edlich, a professor of plastic surgery and biomedical engineering at U.Va.

The Patent Foundation is a not-for-profit corporation affiliated with U.Va. and is responsible for licensing to business and industry the intellectual property discovered and created in University laboratories.