NIST Industrial ImpactCompany: Nonvolatile Electronics, Inc., Eden Prairie, Minnesota A cool magnetic effect discovered a decade ago is becoming hot stuff in a growing marketplace, powering an array of advanced products such as long-lasting computer memory, ultrasensitive devices that count cars or money, and super-comfortable mountain bikes. Many commercial applications of the new “giant magnetoresistive” (GMR) technology can be credited to a small Minnesota company, originally run out of its founder’s home, which used co-funding from NIST’s Advanced Technology Program (ATP) to develop new materials, designs, and techniques that reduced GMR device size and costs. The technical progress achieved in the ATP project enabled Nonvolatile Electronics, Inc. (NVE) to design and demonstrate the first prototype GMR computer memory “cells” (components of integrated circuits, or chips) and produce useful spin-off technologies, all of which promise significant benefits to the nation:
The promise of magnetoresistive random-access memory (MRAM) chips attracted the interest of industry giant Motorola, Inc., and others, which are working with NVE on commercialization, expected as soon as 1999. The technology could eventually capture a sizable share of the $45 billion market for memory and hard-disk-drive products. Motorola, which also acquired a 12 percent stake in NVE, recently announced the formation of a Nonvolatile Memory Technology Center in Texas that will “accelerate the delivery of innovative, high- quality, cost-effective memory technology,” including MRAM. In the meantime, the GMR sensors already are being used at about 80 vehicle-monitoring stations along Pennsylvania highways and others at U.S.-Canadian border crossings, and in a “smart” shock absorber for high-performance mountain bikes. Other emerging uses include counterfeit-detection systems, food processing, factory production lines, antilock braking systems for cars, and electric locks for safes. “We’re uncovering a lot of possibilities right now,” says James Daughton, NVE founder, president, and chief executive officer. Magnetoresistive materials exhibit a change in electrical resistance in the presence of a magnetic field. In 1988, French researchers reported that a sandwich of metals, with alternating layers of magnetic and non-magnetic materials, shows a much greater change in resistance than does a similarly sized piece of a single metal. This effect, dubbed GMR, long has fascinated scientists but only recently has begun to emerge in commercial products, such as high-capacity hard drives. Prior to founding NVE in 1989, Daughton worked at Honeywell, Inc., where he co-invented MRAM technology for defense applications. NVE licensed the technology with the aim of reducing its costs sufficiently to open civilian markets. At the time, production of GMR materials was limited, and it was unclear whether they would function in memory chips or could be produced at reasonable costs, Daughton recalls. In the 3-year ATP project, which ended in 1994, NVE came up with device architectures that increased the density of the circuitry supporting the magnetic cell, helping to reduce the size of Honeywell’s MRAM chips by at least 50 percent. The switch to GMR materials—NVE’s own mixture of nickel, iron, and cobalt—provided a ninefold improvement in read-access time. Yield was enhanced through the use of cutting-edge techniques for assessing the microstructure of the GMR materials. The company also overcame concerns about the durability of the material layers, which are only a few tens of atoms thick. NVE developed new techniques for making layers that are uniform and can withstand high temperatures. The ATP funding enabled NVE to overcome a rocky start, develop the technology base for viable products, and attract the investment by Motorola, Daughton says. The ATP-funded technology has been licensed to Honeywell, which is working on military and avionics applications, and is being incorporated into government computer systems. NVE also is working with another company to develop a GMR-based procedure to detect counterfeit aircraft parts. In the meantime, NVE is selling lots of sensors, which the company says outperform competing devices in terms of size, power consumption, temperature stability, sensitivity, and range of operation. The company sells both standard and customized devices, with or without on-chip electronics that process the signals. Customers in several other industries are convinced already. The GMR sensor is a “great device” for traffic monitoring because it is very sensitive to disruptions in the Earth’s magnetic field (such as those caused by passing cars) and produces a substantial amount of digital data from a small package, according to Harry Sampey, president of Nu-Metrics in Uniontown, Pa. His company added GMR sensors to several of its products and has sold about 8,000 of the improved devices since fall 1997. Nu-Metrics’ new portable traffic-monitoring instrument, which is about the size of a stenographer’s notepad (half the size of the previous model), relies on data from the GMR sensor to determine the type and speed of each passing vehicle. The Japanese plan to order 10,000 of these instruments to perform a national traffic census, Sampey says. The GMR sensors also may help enhance the accuracy of devices for detecting the 100 million to 200 million anti-personnel mines buried around the world, thus saving lives, according to Richard Wold of Geometrics, Inc., in Denver. His company has several military contracts to design and test such systems and has subcontracted NVE to build sensor arrays. Geometrics chose to work with NVE because its GMR sensors continue to be the only ones commercially available and because the company is the only source of customized, highly sensitive devices that operate in very low magnetic fields, Wold says. “We are very positive about the GMR sensors,” he says. “The fact that they are compact, inexpensive, and [operate on] low power makes them attractive for a number of geophysical applications.” Of the emerging applications, NVE is especially interested in ultrasensitive, low-cost antilock brake systems, a potentially huge market. A prototype system installed on a test vehicle survived a trip through Death Valley, Calif., considered the ultimate testing ground, according to NVE. The company still is looking for a car maker interested in adding the new technology to production lines, typically a 4-year phase-in process. January 1999 |