Multimaterial acoustic fibers

Following up on their recent creation of light-sensitive fibers, Professors Yoel Fink and Joannopoulos and their research teams have developed fibers that can detect ("hear") and produce sound ("sing").

These multimaterial fibers are made from a fluorine-based plastic that is commonly used in microphones. By manipulating the arrangement of the fluorine and hydrogen atoms, the researchers were able to keep the molecules asymmetrical and thus make the plastic "piezoelectric," meaning that the molecules change shape when an electric field it applied. In order to generate the electric field, the research team used a conducting plastic containing graphite.

Possible applications of these fibers could include wearable microphones and sensors that monitor bodily functions; loose nets that monitor the flow of water in the ocean; and large-area sonar imaging systems.

This work was supported by MIT's Institute for Soldier Nanotechnologies, the Center for Materials Science and Engineering through the NSF/MRSEC grant, and the U.S. Defense Department's Defense Advanced Research Projects Agency.

Image: Two-dimensional device fabric constructed by knitting the piezoelectric/Fabry–Perot fibers as threads. Inset: Photograph of an individual fiber.