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Rapid prototyping with ice

Dr. Ming Leu, a professor of integrated product manufacturing in the University of Missouri's department of mechanical and aerospace engineering, has a cool idea for rapid prototyping. He is experimenting with using ice instead of plastics for making models of parts and products. "Compared to other prototyping methods, it's cheaper, faster, and much cleaner," says Leu. His approach, called Rapid Freeze Prototyping, is similar to other methods. He uses a nozzle to disperse the material-in this case, droplets of water-onto a surface. But unlike other approaches, Leu's prototypes are developed in a freeze chamber. Rather than creating the prototype layer by layer like current prototyping machines do, Rapid Freeze Prototyping creates a frozen shell first, then fills its interior with water that also freezes. Leu says this approach saves time required for making prototypes. In addition, Leu says his approach makes it easy for manufacturers to build transparent parts. Color parts are made using food coloring in the water. For more information, go to www.umr.edu/~vrpl/rfp.htm .

New laser inspects composite parts

The F-22 and other aircraft that use graphite-epoxy composites in their structures to reduce aircraft weight require extensive inspection for ensuring no flaws exist in the composite's many layers. A

new first-of-its-kind laser inspection system, the LaserUT from Lockheed-Martin, overcomes problems associated with inspecting composite materials. UT stands for Ultrasonic Test. One of the system's lasers generates ultrasound while another detects the resulting signal. "We originally designed a section of an inlet duct as a titanium weldment because it was not practical to inspect this configuration made from composite material," says Bob Rearden, vice-president of Lockheed-Martin and the F-22 program manager. "Now we anticipate switching this component to composite material," he says. Lockheed-Martin expects to reduce inspection time of composite materials by 90% using the LaserUT system. While it used to take up to 24 hours to inspect a single part, the new system inspects the same part for flaws in less than two hours. The system performs high-resolution inspection in one-tenth the time required of current water ultrasonic inspection systems. It inspects complex parts up to 54x27x21 ft. The system is controlled by a Silicon Graphics Onyx II supercomputer capable of real-time signal processing and data analysis. The computer uses a 64-bit R10000 processor with a throughput capacity of 6.4 Gbytes/sec that provides real-time feedback to design engineers for rapid configuration. The laser was developed at Wright-Patterson Air Force Base in Dayton, Ohio. Lockheed-Martin filed several patents on the technology. Its applications include aircraft and automotive parts and bridge structures. For more information, visit www.lockheedmartin.com , call (817) 777-4973, or fax (817) 763-4797.

Chip makers accurately measure temperature

The National Institute of Standards and Technology (NIST) developed a calibration wafer that enables semiconductor chip manufacturers to accurately determine temperatures in their rapid thermal processing systems. Current methods are accurate to within 5 or 6 degrees. The new wafer has thin-film thermocouples that link temperature measurements to the international temperature scale, making it easier to replicate processing conditions at different facilities. Researchers at NIST substituted thin-film thermocouples on the wafer for the wire thermocouples currently used. The thin-film approach eliminates large junctions where pairs of thermocouples meet. "We thought that if you didn't need the wire thermocouple junction at the calibration spot, we could increase accuracy," says Kenneth Kreigder, the NIST researcher who developed the patented technology. The new approach eliminates the heat transfer that occurs at the point where thermocouples meet, which complicates temperature measurement. "It pushes the critical dimensions on line width, squeezing more transistors onto a single chip," says Bill Schuh, a mechanical engineer at Watlow (Richmond, IL), the company that is licensing the technology. Thirteen chip manufacturers are currently evaluating the test wafer. For more information, call (815) 678-2211, e-mail Schuh at [email protected], visit the company's website at www.watlow.com , or fax (815) 678-3961.

Ford sprays molten steel to form auto parts

One of the most time-consuming operations in producing a new automobile is the production of tools and stamping dies for plastic and metal parts. Ford is developing a new process for production of tools and dies called spray-formed tooling. The process starts with a CAD drawing of a part. A ceramic cast of the part is made from a three-dimensional drawing. The cast is placed in a spray chamber where a robot sprays molten steel over the cast, creating a thick steel shell. "When perfected, the spray-formed tooling process will shave millions of dollars and several months off of the production process," says Dr. Charles Wu, director of Ford Manufacturing Systems and Vehicle Design Research Laboratory. Ford estimates the process eliminates more than half of the traditional tool and die production steps. Steps eliminated include most of the machining or chip making, heat treating, and in most cases, the hand-working operations used for making the working and forming areas of the die. Conventional tool and die operations spend the majority of their time and energy machining to get to a finished shape of the working surface area of the die. The new process provides the working surface first, then constructs the die around sprayed detail using a modular die concept. The process is also expected to reduce Ford's production time from 15 to 25 weeks down to less than one month. The company executed a licensing agreement for commercializing the process with Praxair Surface Technologies Inc. through its IP holding company, Ford Global Technologies Inc. Ford also plans to license to other companies. Contact Ford at (313) 594-1993.

Zeolite shows promise for reducing dependency on foreign oil

Researchers at NASA's Marshall Space Flight Center are conducting experiments with zeolite crystals to help reduce the cost of producing gasoline and other petroleum products. Zeolites have many uses. In water, they remove impurities. In laundry detergents, they soften hard water by removing calcium. And in gasoline, they act as catalytic converters, helping reduce pollutants. They may also help increase the yield from a barrel of oil. Zeolites store fuels such as hydrogen, but they don't currently store enough energy to make them desirable for hydrogen-burning engines. NASA's role in improving zeolite involves growing the substance's crystals in space. The crystals grow better in microgravity, according to Dr. Albert Sacco Jr., director for the Center for Microgravity Materials Processing and a former Space Shuttle crew member. "In microgravity, materials come together more slowly, allowing zeolite to form better crystals," says Sacco. He adds that crystals grown on Earth are only 2 to 8 microns, but they need to be at least 200 times larger. For more information, go to www.spd.nasa.gov.news.zeolite.html .

Faster optical communications

Researchers at Mitel (Ottawa, Canada) produced working prototypes of new photonic devices that use Arrayed Waveguide Grating (AWG) for allowing fiber-optic lines to carry more information. Current optical communication networks use Dense Wave Division Multiplexing (DWDM), which handles 16 channels. The new photonic device, called LightRider, goes to 40 channels. Mitel is using a new form of grating called Echelle grating. "It's a way of doing multiplexing with color," says Peter Burke, the company's vice president. "It splits the light much like the way a prism works," he says. The company's material deposition techniques include the capability of depositing thick layers of silica on a silicon base. The company precisely etches the deposition layer, which allows the Echelle grating function to work. A hermetic seal around the device ensures that polarized light does not affect the device's performance. The current prototype conforms to ITU-T grid with 100-GHz channel spacing for use in equipment serving metropolitan networks. "Other applications include ATM switches, routers, and other high-end switches," says Burke. He says the product is being commercialized now. The company also has components for wired and wireless networks and products for application-specific integrated circuits used in medical equipment. Contact Mitel at (613) 592-2122.