Technology Bulletin 257

These materials move when illuminated

Materials like PLZT-a combination of lead, lanthanum, zirconium, and titanium--some day may be used to control space robots and micro machines and transfer information in telephones and optical computers. Such materials are both photovoltaic, producing electricity from light-and piezoelectric, creating motion from electricity. The combination of properties is called photostriction. Photostrictive materials move when illuminated. Now, engineers at Pennsylvania State University are exploring applications for devices that move when light shines on them. Potential uses include remote switches, relays, sound generators, and micro micromotors. Another possible application is scanning tunneling or electron microscopes, where the specimen is placed on a stage in a high vacuum. A properly built platform of PLZT could be moved in the vacuum by shining light from outside without breaching the seal, says electric engineering professor Kenji Uchino. He has already created a two-legged stand that walks very slowly when illuminated. For more information, FAX A'ndrea Elyse Messer at (814) 865-9421.

First all-composite small satellite takes shape

The nation's first all-composite small satellite, designed by Los Alamos National Laboratory and being built through a Los Alamos-industry collaboration, is in the final stages of construction and aiming for an early 1996 launch. "The all-composite structure offers a big advantage in terms of performance," says Steve Knox of Los Alamos' Nonproliferation and International Security Division. "Because the structure is so light-it only weighs 90 pounds-we can deliver to orbit 50 more pounds of payload than a similar-size satellite built with conventional materials." The composite material used for the satellite's framework is a graphite epoxy commonly found in commercial aircraft components. The satellite, called FORTE for Fast On-orbit Recording of Transient Events, will carry electronic equipment for detecting, recording, and analyzing bursts of radio energy arising from near Earth's surface, such as the electromagnetic pulse from a low-technology nuclear explosion. The data FORTE gathers also will be useful for studies of the electrically conducting layer of Earth's atmosphere, and of the physics involved in lightning. For details, FAX John Gustafson at (505) 665-2483.

Space Shuttle main engine sports new turbopump

NASA has successfully completed testing of a new high-pressure liquid-oxygen turbopump, and is ready to fly an upgraded main engine on its first Space Shuttle flight in June. The new pump is expected to increase safety margins and reliability for the Space Shuttle Main Engine (SSME). To create the new turbopump's housing, engineers used a casting process that eliminates all but six of the 300 welds in the current pump. The new pump also uses silicon nitride as the new ball bearing material. Silicon nitride, a type of ceramic, is 30% harder than steel and has an ultra-smooth finish that reduces friction. The new bearings eliminate concerns over excessive wear to the pump-end ball bearing, say NASA engineers. Along with the new turbo- pump, NASA will fly a new two-duct powerhead that is expected to improve fluid flows within the engine system by decreasing pressure, reducing maintenance, and enhancing overall engine performance. It will replace three smaller fuel ducts in the current design with two enlarged ducts. "Credit goes to Pratt and Whitney and Rocketdyne, to Marshall's Science and Engineering Directorate, and to the folks at Stennis Space Center who supported an aggressive test program," says Otto Goetz, SSME deputy project manager. FAX June Malone at (205) 544-5852.

Brainy bike shifts automatically

Imagine riding a bike that finds the right gear-no matter what the incline or the cyclist's energy level. Just as many cars have an automatic transmission, so does a six-speed bicycle built by a group of University of Rochester engineering students. The bike can even learn the nuances of a cyclist riding style and customize shifting accordingly, claim the inventors. The "brain" behind the components is a computer chip programmed to measure wheel speed and how fast the rider is pedaling. A custom algorithm determines chain tension. The cyclist chooses a pedal speed and uses buttons to enter a selection. The chip records how fast the cyclist is supposed to be pedaling. When the rider tires and begins to pedal more slowly, the bike automatically shifts to a lower gear. When the rider pedals faster going down-hill, the bike shifts to a higher gear. Instead of a cable that adjusts the rear derailleur, the chip triggers a motor to move a screw that sends the bike into a different gear. The chip, motor, and two 7.2V batteries weigh less than two pounds. For more information, FAX Tom Rickey at (716) 275-0359.

Used catalytic converters yield precious metals

Engineers at IBC Advanced Technologies, Provo, UT, see precious metals in what others see as automotive scrap. They're using a secondary refining process known as SuperLig(R) to recover platinum, rhodium, and palladium from used catalytic converters and other auto devices. The precious metals sell for hundreds of dollars an ounce. To recover these platinum group metals (PGMs), the catalyst is first leached in a hydrochloric-acid bath. Through a process of solid phase extraction, engineers separate the individual PGMs one at a time. Next, they strip off the separated PGM as a purified concentrate. Once the process is complete, the metal is restored to better than 99.95% purity, say IBC engineers. The process operating cost can be as low as a few dollars per ounce, according to Ronald Bruening, vice president of R&D. "The only chemicals used on a continuous basis are water, hydrochloric acid, and a final precipitating or reducing agent," he adds. FAX IBC at (801) 763-8491.

The check is in the e-mail

Researchers at the Massachusetts Institute of Technology, Cambridge, have developed a software package for automated "reading" of handwritten material that could help streamline the general system of check processing. Americans write more than 50 billion bank checks a year, according to Amar Gupta, a senior research scientist at the Sloan School of Management. Currently, the institution in which a check is deposited has to send the check to the bank from which the funds are withdrawn. Sending only electronic images of scanned checks would save millions in annual postage costs alone. MIT's prototype system claims to read such bank checks and other documents with very high speed and accuracy. Now, banks in the U.S., Britain, and Japan are testing copies of the software. The technology also shows potential for processing forms filed by insurance agents and for handling notes written by healthcare practitioners, say its makers. For more information.

Windows-based CAD product could help cut design time

How many keystrokes does it normally take to create CAD models? Cadkey, Inc. says its new Windows 3-D product will cut that number in half. CADKEY(R) for Windows has accelerator keys and a customizable toolbar that help speed up design time, the developer says. The pop-up toolbar lets users customize their own interface and incorporate commonly used functions. Other features include context-sensitive on-line help, model-to-drawing associativity, hidden-line removal, shading, mass properties, and stereolithography (STL) output for rapid prototyping applications. This is the first Windows version of Cadkey's 2-D and 3-D software. The introductory price of $495 is good through June 1^st, Cadkey says. FAX Ron Cote, (203) 298-8888.

New catalyst makes hardplastic very elastic

Polypropylene in its hard form is found in carpets, containers, and clothing. In its rarer soft form, it ends up in roofing tar and melt adhesives. Now, researchers at Stanford University have found a way to combine the two forms-resulting in a range of new plastics that vary in elasticity. The catalyst is made from a metal compound called metallocene. By controlling the temperature and pressure of the reaction that creates the polymer, scientists have found that they can vary the percentage of crystallites in the polypropylene-and thus its characteristics. The process yields polypropylenes that stretch slightly or are as elastic as natural rubber. The materials might replace more-expensive synthetic elastomers and natural rubber in applications such as car bumpers and athletic shoes, say engineers. The new polypropylenes can be melted and reused, and are readily recycled. For details, FAX Robert Waymouth at (415) 725-0259.

Artificial vision system may prevent flight delays

Pennsylvania State University computer engineers are developing an imaging system to help airline pilots land safely in fog or other situations where they can't see out the windows. The computer-based artificial vision system takes output from a sensor developed for NASA by a commercial partner and combines it with information about the position of the sensor on the plane, the plane's altitude, and a geometric model of the airport. The device, called a passive millimeter wave sensor, detects light at smaller frequencies and longer wavelength than the human eye, so it can "see" in situations where the pilot can't, say engineers. Computer techniques then enhance the image. Key to the system is fast processing to ensure that the pilot receives the information in time to react appropriately, say its creators. Project leader Dr. Rangachar Kasturi expects the system will improve obstacle avoidance and enable planes to land safely in low-visibility conditions, thus avoiding weather-related delays. For details, FAX (814) 865-9421.

Machine guard prevents common accidents

An inexpensive plastic guard invented by a former Cornell University professor promises to prevent accidents involving machine tools and farm equipment. The guard consists of a plastic tube that attaches magnetically to a rotating shaft and spins along with it. If a person comes in contact with the guard, or if clothing or hair become entangled with it, it stops rotating. The tubing's inside diameter is just a bit larger than the outside diameter of the shaft. A disc-shaped magnet fits into the end of the tube. The magnet adheres to the flat outer end of the shaft to hold the tube in place, but the connection is loose enough that if a person touches the tube it will stop rotating while the shaft continues to spin. The device is the invention of Joseph Cambell, who was inspired while designing a filter. Cornell seeks to patent the device. You can reach Cambell c/o the Agricultural Engineering Dept., FAX (607) 255-4080.