News Release

AIP awards Industrial Physics Prize to inventor of digital x-ray detector

COLLEGE PARK, MARYLAND, 30 October 2009 — The American Institute of Physics (AIP) is awarding the 2010 Prize for Industrial Applications of Physics next month to Robert Street of the Palo Alto Research Center (PARC) in California. The prize is supported by General Motors.

Street's pioneering work at PARC in the early 1990s led to the development of flat-panel digital X-ray detectors, a commercially-available technology that has replaced traditional film X-ray machines for many medical applications.

These devices can be found in hospitals and clinics across the United States today, where they assist doctors in diagnosing diseases like breast cancer, helping to save lives. AIP governing board member Rudy Ludeke will present Street with the $10,000 prize and a certificate at a ceremony on November 11 during the AVS 56th International Symposium & Exhibition in San Jose, CA.

The secret to Street's flat-panel digital X-ray detector is a dense glass-like material known as amorphous silicon that can be vacuum deposited onto surfaces and formed into electronic devices. Today, it is a standard material used in the manufacture of $100 billion dollars worth of electronics sold each year -- devices like laptop displays and flat panel TV sets.

In the 1980s, the material was just starting to find its way into electronics, and Street spent much of that decade studying the basic properties of this material. In the mid-1980s, a PARC team designed a new sensor array for a photocopier and printer based on amorphous silicon.

Street soon realized that a similar sensor array using the same material might be able to detect X-rays and capture images of the human body completely electronically. By the early 1990s, he and his colleagues had worked out many of the technological hurdles necessary to do so.

"We went ahead and made the first X-ray imaging device," Street says. He recalls that he never doubted whether such a detector could be built. The only question was whether the device would be effective in a clinical setting, and could be manufactured with the reliability needed for a medical device.
Early tests showed promise, and in 1996, PARC spun off a start-up company called dpiX, Inc. that began commercializing this digital X-ray technology, which has since become a large and growing segment of the medical imaging industry.

To take just a single example of how digital X-ray technology is impacting medicine, about half of all mammography systems in the United States today are digital -- up from about a third just a year ago. This growth has come in part because the results of a large study comparing digital with film mammography involving 50,000 women showed in 2005 that the diagnostic accuracy of digital is just as good as film overall.

Though digital systems tend to be more expensive, they offer significant advantages in terms of image quality and electronic storage and manipulation. Moreover, digital systems have proven more accurate at diagnosing breast cancer in women under the age of 50, women with dense breasts, and premenopausal or perimenopausal women.

Born and raised in Birmingham, England, Robert Street received a Ph.D. in 1971 from Cambridge University for work on the physics of chalcogenide glasses. He was a postdoc at Sheffield University, and then a visiting scientist to the Max Planck Institute in Stuttgart, Germany. He joined PARC in 1976, where he is now a Senior Research Fellow. He is also a Fellow of the American Physical Society and the Materials Research Society.

His current research explores finding novel low-cost and large-area electronics for applications ranging from new flat panel displays to radiation sensors. Projects he has been involved with in recent years include ink-jet printing of organic electronic devices, constructing flexible electronic displays, developing technology for truck-size scanners for homeland security, and researching new solar cell structures. As of 2009, Street is the author of about 400 papers, several books and book chapters, and 60 patents.
Street and his wife live in Palo Alto, CA. They have two grown children and one grandchild.

He will receive his prize at an awards ceremony and reception beginning at 6:15 p.m. on Wednesday, November 11, 2009 in Ballrooms A2-7 of the San Jose Convention Center. The ceremony is part of the AVS 56th International Symposium & Exhibition, which convenes from November 8-13 in San Jose, CA. See:

About the Prize

Established in 1977, the Prize for Industrial Applications of Physics recognizes outstanding contributions by an individual or individuals to the industrial applications of physics.  The American Institute of Physics (AIP) Corporate Associates and the American Physical Society (APS) alternate in co-sponsoring this $10,000 award with General Motors.  Where the AIP award recognizes scientists who have developed proven technologies, the APS award recognizes research that has excellent potential for future success. For more information, see:

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