Img/2012/3/16/polyi.jpgWashington: Perhaps inspired by a chameleon`s changing colours, engineers have developed a polymer that reproduces rough, smooth textures as and when required.
"By changing the voltage applied to the polymer, we can alter the surface from bumpy to smooth and back again," said Xuanhe Zhao, assistant professor of mechanical engineering and materials science at Duke`s University Pratt School of Engineering.
"There are many instances, for example, when you`d want to be able to change at will a surface from one that is rough to slippery and back again," added Zhao, the journal Advanced Materials reports.
Other potential usages include creating surfaces that are self-cleaning and water-repellant. On a more fanciful note, Zhao described the possibility of creating rubber gloves whose fingerprints could be changed on demand, according to a Duke statement.
"The changeable patterns we have created in the laboratory include circles and straight and curved lines, which are basic elements of fingerprints," Zhao said
Scientists have long been able to create different patterns or textures on plastics through a process known as electrostatic lithography, etching patterns onto a surface from an electrode located above the polymer. However, once the patterns have been created, they are set permanently.
"We invented a method which is capable of dynamically generating a rich variety of patterns with various shapes and sizes on large areas of soft plastics or polymers," Zhao said.
"This new approach can dynamically switch polymer surfaces among various patterns ranging from dots, segments, lines to circles," said Qiming Wang, student in Zhao`s lab and study co-author.
"The switching is also very fast, within milliseconds, and the pattern sizes can be tuned from millimeter to sub-micrometer," added Wang. "These elements can be dynamically patterned and changed on a glove surface that covers fingertips," he added.