THE MAGIC TOUCH
An artificial finger developed by a Tech researcher could revolutionize the textile industry by changing the way fabric quality is measured.
Written by Leslie Woodard
Crisp and cool cotton sheets on a hot summer night. Warm flannel shirts on a below-freezing winter morning. A fine linen shirt paired with a favorite silk tie. Each with its own unique feel against the skin. But choosing higher quality sheets, or determining if that fine shirt really is worth the price has, up until now, been left to methods which, at best, are extremely subjective. Seshadri S. "Ram" Ramkumar, Ph.D., a researcher at Texas Tech University's International Textile Center is changing that with the touch of a finger.
Ramkumar has developed an objective quality evaluation method that uses an artificial polymeric finger, which could revolutionize the way fabric quality is measured. Polymers, which can be either natural or synthetic, include materials such as polyester and nylon. The particular polymer used in Ramkumar's project is a kind of rubber that has some flexibility. The finger simulates the way fabric is felt with the human hand, but also assigns a standard measurement to each fabric, a system that is faster and certainly more accurate than using human touch or other established industry methods.
The quality of fabric, or "hand" as it is known in the textile industry, is still best measured by the running of fabric between finger and thumb. Hand has long been a time-consuming and costly test for manufacturers. Fabric testing methods, such as the Kawabata Evaluation System for Fabrics (KES-F) and the Fabric Assurance by Simple Testing (FAST) method measure hand-related properties, but are still too expensive, cumbersome and time-consuming.
"When a consumer goes into a store, they may rub a jacket or sweater between their fingers to decide its quality. The problem is the finger test is not very accurate," Ramkumar said. "The idea is to create some kind of industry-wide rating system for fabric, similar to the one currently used with cotton fiber. That way, consumers will know whether garments made of two fabrics that feel completely different are of similar quality."
Ramkumar initiated the project while at the School of Textile Industries, University of Leeds, England. He began by collaborating with David Wood, Ph.D., and Kathryn Fox, M.S. Dentistry, of the Division of Restorative Dentistry, Leeds Dental Institute, to create the original prototype of the artificial finger, which ultimately measures the frictional properties of fabric.
Ramkumar's artificial finger has been molded into the shape and size of an average human finger, and looks and feels like a real finger on the tip. It is made of a rubber-like material called polysiloxane. The finger is the integral part of a machine that simulates human touch. Ramkumar has tested textures of paper towels, medical and hygienic cloths and even baby diapers.
Ramkumar explained that, for example, a baby cannot say whether a cloth diaper feels good. Having a rating system would assess a value to the fabric.
"You may say a certain cotton fiber is not good," he said. "One fiber has X quality and another has Y quality, but it may make very little difference in the finished fabric. Now we can say this fabric has this value. Period."
As innovative as the system is, it appears to be a relatively simple process. "The polymeric finger, which is rubbed over the fabric, sends an electronic signal to the system, which is used to measure hand during production," Ramkumar said. "Specifically, I just place the material on a small platform. The pulley creates a to-and-fro motion. The polymeric finger touches the fabric where the nerve endings meet in a human finger. The finger simulates what a human finger would feel."
The machine assigns a number that rates the quality of the material. The lower the number, the better the quality, Ramkumar said. The numbers are in Pascal, which is a pressure unit.
Continuing his research at Texas Tech's International Textile Center, Ramkumar must further prove his system over a wider range of materials and gather supporting data. Work has begun on patenting the system.
"My next task will be to construct a smaller prototype, which will be easier to commercialize," Ramkumar said. "Right now the machinery is too cumbersome for routine use by manufacturers."
Ramkumar believes other industries also will benefit from the research. He says the artificial finger research also has implications for the medical field for creams and lotions, as well as the cosmetics industry in terms of how products feel to the skin.
Ramkumar's pioneering research has been cited in many textile journals such as Textile World, Textile Horizons, America's Textiles International and A.T.A. Journal, an Asian journal on textiles and apparel. He recently received the Chartered Physicist Award from the Institute of Physics in London. In July 2000, he was invited to speak at the Harvard School of Public Health and to present posters at the prestigious Frontiers of Science "Gordon" Conference on tribology, which broadly covers the field of friction and draws on knowledge from the fields of physics, chemistry, metallurgy and engineering. Additionally, Ramkumar received the Fiber Society's Graduate Student Original Research Paper Award in 1998 for his innovative work on the hand evaluation of fabrics.
With the patent for the artificial finger and rating process nearing completion, Ramkumar and Texas Tech's International Textile Center are again on the cutting -- or measuring -- edge of textile and fabric industry technology. All with the touch of a finger.
Story produced by the Office of Communications and Marketing
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