APS News

July 2008 (Volume 17, Number 7)

Finalists Vie for APS Industrial Physics Prize

Five finalists are competing for the first APS Prize for Industrial Applications of Physics, launched this year. As reported in the January APS News, the prize, sponsored by General Motors and presented biennially, is intended to recognize cutting-edge technologies, and is especially targeted at physicists working in smaller companies.

To encourage nominations, the selection process has two stages: first, preliminary nominations are submitted by the deadline of April 1. The selection committee picks a small number of finalists, who then submit more complete nomination packages by July 1, from among which the committee will recommend the recipient to the APS Executive Board.

This year 16 preliminary nominations were received. “I was delighted that there were so many nominations of high quality,” said Greg Meisner, the selection committee chair. “But it made choosing the finalists very difficult.”

The finalists selected by the committee are:

Jason Ensher and Susan Hunter

Jason Ensher and Susan Hunter applied tunable External Cavity Laser Diodes (ECLDs) to holographic data storage. Holography holds great potential for storing information because holograms can be multiplexed in three dimensions, rather than being limited to the surface of the storage medium. InPhase Technologies spun off from Bell Labs in 2000 to commercialize a unique chemistry for the storage media and the architecture for a holographic drive, with a storage lifetime of 50 years and density and cost comparable to magnetic tape. However, the most daunting remaining challenge was finding a light source for the drive. Commercial holography requires a laser with spectroscopic quality, in a small robust package that costs a small fraction of the total $18,000 drive.

ECLDs have been used since the early 1990s to apply semiconductor laser diodes to high-resolution spectroscopy, but while the performance specifications met InPhase’s needs, the cost to scale up efficiently to manufacturing volumes was too high: Ensher and Hunter aimed for a cost 10 times lower than ECLDs of comparable performance. The usual approach is to make the ECLD continuously tunable in a single mode using an expensive cavity and very precise tuning mechanism. Ensher and Hunter realized it would be much cheaper to design a cavity that minimizes laser mode-hops that can also detect when the laser mode is degrading thanks to the incorporation of a mode sensor combined with a digital control algorithm.

Ensher and Hunter’s ECLD automatically senses the laser mode and feeds back this information to correct the laser cavity length–they call this Automatic Mode Control (AMC)–thereby enabling the ECLD to produce holograms for hours at a time, over a wide temperature range. The entire laser fits into a small package measuring 5 cm x 14 cm x 3 cm. Manufacturing of the first prototypes began in May 2008. The first customers for holographic storage are likely to be TV networks and major media companies. Further in the future, holography might be the basis for the next generation of consumer optical storage devices, selling millions of units per year.

As a graduate student in the mid 1990s, Ensher worked with Eric Cornell and Carl Wieman at the University of Colorado on laser cooling and trapping of atoms, which led to the creation of the first Bose-Einstein condensate of dilute alkali gases. After a postdoctoral position at the University of Connecticut, Ensher worked with laser diodes for ILX Lightwave, and then worked on tunable lasers for Precision Photonics Corp. He joined InPhase Technologies in 2006.

Hunter began working on 3D optical data storage and specialized lasers as a graduate student at the University of California, San Diego. She continued that work over an 11-year career at Hewlett-Packard (later Agilent Technologies). She joined InPhase Technologies in 2005.

Andrew McDowell

Andrew McDowell developed the first hand-held detector capable of nuclear magnetic resonance (NMR) spectroscopy of hydrogen. NMR techniques are popular because of their broad applicability to the study of chemical, physical and spatial properties of samples, without damaging or destroying those samples. Modern NMR instruments, while sophisticated, are large, expensive, must be installed in special rooms, and require periodic maintenance. This makes it difficult to bring NMR techniques out of the lab into applied industrial settings on the “factory floor.”

McDowell set out to reduce the size and cost of NMR instrumentation by combining nanoliter volume “microcoil” detectors with small permanent magnets, which can generate magnetic fields of between 1 and 2 Tesla. While this is weak compared to superconducting NMR magnets, it is strong enough for portable NMR applications. To allow the operation of the tiny coils in the weak field, he added a counterintuitive “auxiliary inductor” to the traditional tuning circuit.

One of the most critical application areas for handheld NMR is the detection of pathogenic bacteria in biological samples, such as blood. Contaminated blood can lead to sepsis and death if not diagnosed and treated quickly. Over 200,000 people in the US die each year from sepsis. Combined with immuno-magnetic labeling of target entities, McDowell’s technology results in unprecedented sensitivity and speed of detection. The technology allows for detection and identification of bacteria in blood samples within minutes, compared to 12 to 24 hours for conventional blood cultures. A start-up company based in Albuquerque, New Mexico, called nanoMR, has been formed to commercialize this technology.

McDowell earned his PhD in physics from Cornell University and was a postdoctoral fellow at Washington University in St. Louis before joining the faculty of Knox College. He worked as a scientist for New Mexico Resonance prior to co-founding ABQMR in 2005.

Roy Rand

As the vice president for research and development of a small start-up company, Imatron, Inc., Roy Rand played a key role in the development of an innovative cardiac CT scanner. The scanner Imatron developed had much shorter scan time than conventional CT scanners at the time, making possible clear images of a rapidly moving heart.

Conventional CT scanners use an x-ray tube that is swept mechanically; the Imatron scanner works with no moving parts–the x-ray beam is swept electronically, and therefore can be swept much faster. To do this, x-rays are generated using an electron beam that traverses a stationary tungsten X-ray target. For this application, an electron beam with high power (up to 140 kW) and a small beam spot (much less than 1 mm) was needed. These parameters hadn’t been thought achievable, due to space charge repulsion.

Rand began a theoretical study, and realized that the necessary conditions could be achieved by neutralizing the space-charge of the electron beam and using “gas focusing.” Rand’s study resulted in a beam-optics system utilizing neutralization of the beam by means of its own beam-generated plasma. Ions were extracted from selected sectors of the beam by clearing electrodes while the pressure of the background chamber gas was controlled automatically. In this system most of the focusing was due to beam self-forces, while the focus adjustment and shaping of the beam spot were achieved by means of solenoid and quadrupole coils.

Rand’s work resulted in 25 patents and a publication in the Journal of Applied Physics. Electron Beam Computed Tomography, as the technology is called, is used to detect calcification of coronary arteries, which is a heath risk factor that cannot be quantitatively measured with as much accuracy by any other device. Competing technologies expose the patient to a much greater radiation dose.

Rand earned his B.Sc. and Ph.D. from University College London. From 1960 to 1981, Rand was employed at various times at University College London, Daresbury Nuclear Physics Laboratory in England, Stanford University in California, and the University of Western Australia. He worked in high energy physics, nuclear physics, and accelerator physics. In 1981 he was asked by a former colleague, Douglas Boyd, to join him in founding Imatron as Vice President of Research and Development. Imatron manufactured and sold about 200 cardiac CT scanners throughout the world. The company was eventually bought out by General Electric in 2001, and Rand retired shortly after. Since then he has consulted for various companies on electron beam technology and is currently involved in designing an electron beam baggage scanner and explosives detector.

Richard Ruby, John Larson and Paul Bradley

Sleek thin cell phones packed with features are possible thanks to work by Richard Ruby, John Larson, and Paul Bradley of Avago Technologies. They developed filters and duplexers using FBAR (free standing bulk acoustic resonator) technology. The FBAR resonator consists of a piezoelectric layer sandwiched between two electrodes. The device resonates in the GHz frequency range, and because it is a mechanical resonator, the Q (quality factor) is exceptionally high.

In the early 1980s FBAR technology looked promising, but by the end of the decade researchers had lost interest in the technology due to several issues: the piezoelectric used, ZnO, was difficult to process; the gold electrodes used also had processing problems and poor Q; and it was difficult to make free- standing membranes. In addition, a simpler competing technology, surface acoustic wave (SAW) filters, already existed.

Ruby began working on the FBAR technology in 1993. He developed it into a practical device by using a different piezoelectric material, aluminum nitride, different electrodes, and a surface micro-machined process to create the free standing membrane.

Larson joined the project in 1996, working on modeling the device and on controlling the frequency across a whole wafer of filters. Paul Bradley, who joined the group in 1997, worked on modeling and designing filters using the FBAR resonator as the “engine.” He measured and modeled the package as well as the device and began designing a PCS duplexer, which would become critical for cell phones.

Cell phones shrank dramatically with the first duplexers using FBAR technology. Duplexers, which separate transmitted signals from received signals, were previously made from ceramic, and were much larger. The FBAR filters are typically the size of a grain of sand. The first FBAR duplexers were sold in 2000, and now over a billion FBAR filters have been sold.  

FBAR filters

Four FBAR filters in an all-sillicon package (WLP) placed on a single grain of rice

Rich Ruby obtained his PhD from the University of California, Berkeley, in 1984. Ruby then joined HP Labs. In 1993, he began researching FBAR technology as a means to making high-Q, ultra-miniature filters for rf applications. In 1999, Ruby became part of Agilent (a spin-off of HP) and moved to the Wireless Semiconductor Division of Agilent. This division became part of a new spin-off to a company called Avago Technologies.

John Larson earned his Ph.D. from Stanford University in 1971, then joined H-P Laboratories in 1972. Larson began working with Ruby in 1996 and began modeling, giving valuable insight as to the acoustics of the device. Later, he found a low-cost manufacturable method to “tune” all the filters on a silicon wafer to one frequency, and invented many new tools to improve the manufacture of FBAR.

Paul Bradley received a PhD in physics from UC Berkeley in 1988. From 1989-1997 he worked at Hypres, a low temperature superconductivity fabrication and design company in Elmsford, N.Y. He joined the HP Labs/Agilent Labs/Avago team in 1997 and became the key designer of the early filters and most important, the PCS duplexer (a particularly demanding filter-pair used in many cell phones today).

Philip Wyatt

Wyatt pioneered the commercialization of laser light scattering (LLS), a method with much practical benefit for both the chemical and pharmaceutical industries. Wyatt first became interested in the practical applications of the classical inverse scattering problem in 1967, suspecting it might prove to be a useful tool for identifying bacteria and spores, especially those that might be deployed in biological warfare. He modified a traditional light scattering photometer by replacing the usual Hg arc lamp with the then-newly- available HeNe laser source, and used his prototype to demonstrate its ability to differentiate between some species in liquid, to measure physical properties of a bacterial cell, and to detect the effects of antimicrobials within a few minutes.

He founded a company to commercialize these laser-based instruments, which closed after 12 years, and founded the Wyatt Technology Company (WTC) in 1982 with funding from the Department of Defense. Over the  next 20 years, WTC’s multiangle light scattering photometer moved from use by manufacturers of synthetic polymers to the pharmaceutical industry, which recognized the potential of such instruments in the  development of new biologicals, including vaccines and protein-based products. By the turn of the century, the product line had expanded to include differential refractometers and devices to fractionate liquid dispersed samples.

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Editor: Alan Chodos
Staff Writer: Ernie Tretkoff
Contributing Editor: Jennifer Ouellette
Science Writing Intern: Nadia Ramlagan

July 2008 (Volume 17, Number 7)

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Articles in this Issue
2008 US Physics Team Training Camp: Sights Set on Vietnam
PhysicsCentral Takes on a New Look and Feel
Finalists Vie for APS Industrial Physics Prize
DAMOP Holds Annual Meeting in State College, PA
Living on the Air in Saint Louis
Proposed Constitutional Amendments Regarding Updating APS Treasurer Position to Treasurer/Publisher
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Members in the Media
This Month in Physics History
Zero Gravity: The Lighter Side of Science
Washington Dispatch
2008 General Election Preview