New Fibers Can See, Hear, Speak

July 14, 2010— -- Clothing that can see, hear and even talk is being developed by scientists from the Massachusetts Institute of Technology.

By adding light- and sound-sensitive materials to synthetic fibers, the researchers are creating a new class of intelligent materials that could have a huge range of potential applications, from undetectable microphones to sophisticated medical sensors.

"Fibers are, for the most part, static," said Yoel Fink, a scientist at MIT and a co-author of the Nature Materials paper that describes the research.

Cotton, polyester, wool and other materials look good and feel comfortable, but that's about all they can do. They are, in other words, dumb. "We want to see how sophisticated a fiber can become to see how many different functions we can put into it," said Fink.

The key to Fink's fibers is a special manufacturing process that is remarkably similar to how saltwater taffy is made.

To create the sound-sensitive fibers the scientists first make a thick rod, or preform. Inside that preform are thick layers of graphite electrodes, a plastic piezoelectric commonly found in microphones and light-sensitive materials. The MIT scientists heat up the rod and stretch it into miles of nanometer-sized fibers with thin layers that, besides their size, are otherwise identical to the original preform.

Here's the trick: Ordinarily, heating up these materials would cause them to mix, separating the layers and rendering the fibers useless. Fink and his colleagues have created a unique way to stretch those fibers without destroying the underlying architecture.

It's a simple tweak, but one that has enabled Fink to create an ever expanding class of fibers with new and unique abilities.

"He's certainly gotten a lot of mileage out of it," said Eli Yablonovitch, a scientist at the University of California, Berkeley, who reviewed the recent paper. "Yoel is a very creative guy, and this research is in line with that creativity."

Last year Fink and his colleagues used this technique to create fibers that can see. By incorporating piezoelectric materials into the fibers, he has created a fiber that can hear and speak as well as see.