Home / Knowledge / News / Textiles / Researchers create fibers that can detect & produce sound
Researchers create fibers that can detect & produce sound
17
Jul '10
For centuries, "man-made fibers" meant the raw stuff of clothes and ropes; in the information age, it's come to mean the filaments of glass that carry data in communications networks. But to Yoel Fink, an associate professor of materials science and principal investigator at MIT's Research Lab of Electronics, the threads used in textiles and even optical fibers are much too passive. For the past decade, his lab has been working to develop fibers with ever more sophisticated properties, to enable fabrics that can interact with their environment.

In the August issue of Nature Materials, Fink and his collaborators announce a new milestone on the path to functional fibers: fibers that can detect and produce sound. Applications could include clothes that are themselves sensitive microphones, for capturing speech or monitoring bodily functions, and tiny filaments that could measure blood flow in capillaries or pressure in the brain.

Ordinary optical fibers are made from a "preform," a large cylinder of a single material that is heated up, drawn out, and then cooled. The fibers developed in Fink's lab, by contrast, derive their functionality from the elaborate geometrical arrangement of several different materials, which must survive the heating and drawing process intact.

The heart of the new acoustic fibers is a plastic commonly used in microphones. By playing with the plastic's fluorine content, the researchers were able to ensure that its molecules remain lopsided — with fluorine atoms lined up on one side and hydrogen atoms on the other — even during heating and drawing. The asymmetry of the molecules is what makes the plastic "piezoelectric," meaning that it changes shape when an electric field is applied to it.

In a conventional piezoelectric microphone, the electric field is generated by metal electrodes. But in a fiber microphone, the drawing process would cause metal electrodes to lose their shape. So the researchers instead used a conducting plastic that contains graphite, the material found in pencil lead. When heated, the conducting plastic maintains a higher viscosity — it yields a thicker fluid — than a metal would.

Not only did this prevent the mixing of materials, but, crucially, it also made for fibers with a regular thickness. After the fiber has been drawn, the researchers need to align all the piezoelectric molecules in the same direction. That requires the application of a powerful electric field — 20 times as powerful as the fields that cause lightning during a thunderstorm. Anywhere the fiber is too narrow, the field would generate a tiny lightning bolt, which could destroy the material around it.

Despite the delicate balance required by the manufacturing process, the researchers were able to build functioning fibers in the lab. "You can actually hear them, these fibers," says Chocat, a graduate student in the materials science department. "If you connected them to a power supply and applied a sinusoidal current" — an alternating current whose period is very regular — "then it would vibrate. And if you make it vibrate at audible frequencies and put it close to your ear, you could actually hear different notes or sounds coming out of it." For their Nature Materials paper, however, the researchers measured the fiber's acoustic properties more rigorously. Since water conducts sound better than air, they placed it in a water tank opposite a standard acoustic transducer, a device that could alternately emit sound waves detected by the fiber and detect sound waves emitted by the fiber.


Must ReadView All

Courtesy: Michael Kors

Fashion | On 25th Jul 2017

Michael Kors to acquire Jimmy Choo

Global fashion luxury brand Michael Kors Holdings Limited has reached ...

Apparel/Garments | On 25th Jul 2017

VF Corp posts $2.4 billion revenue for Q2 2017

VF Corporation has recorded revenue of $2.4 billion, up 2 per cent,...

Textiles | On 25th Jul 2017

Global growth to pick up in 2017 and 2018: IMF

The pickup in global growth anticipated in the April World Economic...

Interviews View All

Headhonchos
Indian textile value chain

'One nation, one tax' is a great concept

Yash Maniyar
Rekha Maniyar

Indian fashion market is growing at a staggering rate

Jim Desai
Blaiva Fabricaa

Fashion industry likely to remain labour-intensive in coming years

Kevin Nelson
TissueGen

Kevin Nelson, Chief Scientific Officer, TissueGen discusses the growing...

Eric Scholler
Groz-Beckert

The Indian market has huge potential in technical textiles, and by far,...

Lynda Kelly
Suominen Corporation

Suominen Corporation is a manufacturer of nonwovens as roll goods for...

Mike Hoffman
Gildan Activewear SRL

Gildan Activewear, a manufacturer and marketer of branded clothing and...

Karan Arora
Karan Arora

Bridal couture created with rich Indian heritage, exquisite craftsmanship...

Madhu Jain
Madhu Jain

She grew up in the walled city of Old Delhi, completed her studies, and...

Press Release

Press Release

Letter to Editor

Letter to Editor

RSS Feed

RSS Feed

Submit your press release on


editorial@fibre2fashion.com

Letter To Editor






(Max. 8000 char.)

Search Companies





SEARCH

July 2017

Subscribe today and get the latest update on Textiles, Fashion, Apparel and so on.

news category


Related Categories:

Planning to Take the Leap towards
Sustainability?

Do you see sustainability as a route to business growth?

Yes No

Do you think the sustainability space has the needed tools and resources available for a business to lead change?

Yes No

Do you think adopting a sustainable approach will be a profitable move for your business?

Yes No

Do you want the world to know about your sustainability journey and your business’ environmental footprint?

Yes No

Thanks for your valuable feedback. Claim your free latest sustainability e-book.


E-News Insight
Subscribe Today and Get the
Latest News Update in Your Mail Box.
Advanced Search



X