To: Paul Engel who wrote (77158 ) 3/24/1999 8:23:00 AM From: Boplicity Respond to of 186894
Bell Labs Researchers Use Miniature Rubber Stamps to Create Microscopic Devices ATLANTA--(BUSINESS WIRE)--March 24, 1999--Researchers at Lucent Technologies' Bell Labs have developed new techniques for stamping sub-micron features on glass, plastics, metals and other materials. The potential applications include optical communications devices and plastic transistors with the smallest features yet, which may be used for products as diverse as luggage tags and flexible displays. The new process involves making reusable rubber stamps with extremely small features - at times, only 0.00001 inch wide - and then using the stamps to make high-performance optical and electronic devices. The stamps are made by pouring liquid rubber onto a prototype device made of patterned silicon. The rubber solidifies and is peeled away from the silicon, creating a perfect reproduction of the microscopic silicon relief pattern. "Techniques that use these rubber stamps and molds provide simple, low-cost alternatives to conventional lithography," said Bell Labs chemist John Rogers, who will discuss his research Friday (March 26) at the centennial meeting of the American Physical Society. "The techniques also may lead to novel applications because we can now print features on rough or curved surfaces, such as optical fiber, and on materials that are incompatible with standard lithographic techniques." To make plastic transistors, Rogers and his colleagues first inked the rubber stamp - in this case, a precise replica of a patterned silicon wafer - with an organic ink. They then stamped a gold-coated plastic film and etched away the unprinted area of the gold, leaving high-resolution circuit patterns; the special ink protected the gold from being etched. Next, they stripped away the ink with ultraviolet light, exposing the underlying gold, and deposited organic semiconductor material on the gold pattern. Using this technique, the team was able to create fully functioning plastic circuits with features as small as 0.2 micron - roughly 0.00001 inch wide - which is 500 times smaller than plastic transistors produced with previous techniques. The feature sizes also are comparable to those on today's state-of-the-art silicon chips. Rogers' team also created resonators for plastic-based lasers that could potentially be used in optical communications. In all lasers, light waves are amplified as they bounce between a pair of mirrors. Rogers and his colleagues used a flat rubber stamp with a series of raised lines only 0.3 microns wide to define lines of gold on plastic. They then etched away the regions not protected by the gold, creating surface-relief, resonator structures with the desired pattern. "These lasers had operating characteristics that were nearly identical to those produced by lasers manufactured with high-resolution photolithography," Rogers said. In another demonstration of the nanomolding technique, Rogers stamped microcoils on optical fiber by rolling the fiber over a rubber stamp with raised lines. By flowing current through the microcoils hundreds of turns per centimeter of fiber - it is possible to dynamically tune the optical characteristics of the fiber, a potentially important capability for future high-capacity optical networks that may demand more than simple passive elements within the fiber. Lucent Technologies, headquartered in Murray Hill, N.J., designs, builds and delivers a wide range of public and private networks, communications systems and software, data networking systems, business telephone systems and microelectronics components. Bell Laboratories is the research and development arm for the company. For more information on Lucent Technologies, visit the company's web site at lucent.com .