Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Making ‘nanospinning’ practical --Nanofibers have a dizzying range of possible applications, but they’ve been prohibitively expensive to make. MIT researchers hope to change that.

Abstract:
Nanofibers — strands of material only a couple hundred nanometers in diameter — have a huge range of possible applications: scaffolds for bioengineered organs, ultrafine air and water filters, and lightweight Kevlar body armor, to name just a few. But so far, the expense of producing them has consigned them to a few high-end, niche applications.

Making ‘nanospinning’ practical --Nanofibers have a dizzying range of possible applications, but they’ve been prohibitively expensive to make. MIT researchers hope to change that.

Cambridge, MA | Posted on November 19th, 2012

Luis Velásquez-García, a principal research scientist at MIT's Microsystems Technology Laboratories, and his group hope to change that. At the International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications in December, Velásquez-García, his student Philip Ponce de Leon, and Frances Hill, a postdoc in his group, will describe a new system for spinning nanofibers that should offer significant productivity increases while drastically reducing power consumption.

Using manufacturing techniques common in the microchip industry, the MTL researchers built a one-square-centimeter array of conical tips, which they immersed in a fluid containing a dissolved plastic. They then applied a voltage to the array, producing an electrostatic field that is strongest at the tips of the cones. In a technique known as electrospinning, the cones eject the dissolved plastic as a stream that solidifies into a fiber only 220 nanometers across.

In their experiments, the researchers used a five-by-five array of cones, which already yields a sevenfold increase in productivity per square centimeter over even the best existing methods. But, Velásquez-García says, it should be relatively simple to pack more cones onto a chip, boosting productivity even more. Indeed, he says, in prior work on a similar technique called electrospray, his lab was able to cram almost a thousand emitters into a single square centimeter. And multiple arrays could be combined in a panel to further increase yields.

Because the new paper was prepared for an energy conference, it focuses on energy applications. But nanofibers could be useful for any device that needs to maximize the ratio of surface area to volume, Velásquez-García says. Capacitors — circuit components that store electricity — are one example, because capacitance scales with surface area. The electrodes used in fuel cells are another, because the greater the electrodes' surface area, the more efficiently they catalyze the reactions that drive the cell. But almost any chemical process can benefit from increasing catalysts' surface area, and increasing the surface area of artificial-organ scaffolds gives cells more points at which to adhere.

Another promising application of nanofibers is in meshes so fine that they allow only nanoscale particles to pass through. The example in the new paper again comes from energy research: the membranes that separate the halves of a fuel cell. But similar meshes could be used to filter water. Such applications, Velásquez-García says, depend crucially on consistency in the fiber diameter, another respect in which the new technique offers advantages over its predecessors.

Existing electrospinning techniques generally rely on tiny nozzles, through which the dissolved polymer is forced. Variations in operating conditions and in the shape of the nozzles can cause large variation in the fiber diameter, and the nozzles' hydraulics mean that they can't be packed as tightly together. A few manufacturers have developed fiber-spinning devices that use electrostatic fields, but their emitters are made using much cruder processes than the chip-manufacturing techniques that the MTL researchers exploited. As a consequence, not only are the arrays of tips much less dense, but the devices consume more power.

"The electrostatic field is enhanced if the tip diameter is smaller," Velásquez-García says. "If you have tips of, say, millimeter diameter, then if you apply enough voltage, you can trigger the ionization of the liquid and spin fibers. But if you can make them sharper, then you need a lot less voltage to achieve the same result."

The use of microfabrication technologies not only allowed the MTL researchers to pack their cones more tightly and sharpen their tips, but it also gave them much more precise control of the structure of the cones' surfaces. Indeed, the sides of the cones have a nubby texture that helps the cones wick up the fluid in which the polymer is dissolved. In ongoing experiments, the researchers have also covered the cones with what Velásquez-García describes as a "wool" of carbon nanotubes, which should work better with some types of materials.

Indeed, Velásquez-García says, his group's results depend not only on the design of the emitters themselves, but on a precise balance between the structure of the cones and their textured coating, the strength of the electrostatic field, and the composition of the fluid bath in which the cones are immersed.

The MIT researchers' work was funded in part by the U.S. Defense Advanced Research Projects Agency.

Written by Larry Hardesty, MIT News Office

####

For more information, please click here

Contacts:
Caroline McCall
MIT News Office
E:
T: 617-253-1682

Copyright © MIT

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Creation of 'Rocker' protein opens way for new smart molecules in medicine, other fields December 18th, 2014

How does enzymatic pretreatment affect the nanostructure and reaction space of lignocellulosic biomass? December 18th, 2014

Silicon Valley-Based Foresight Valuation Launches STR-IP™, a New Initiative for Startups to Discover the Value of Their Intellectual Property December 18th, 2014

Iranian Scientists Use Nanotechnology to Increase Power, Energy of Supercapacitors December 18th, 2014

Govt.-Legislation/Regulation/Funding/Policy

Zenosense, Inc. - Hospital Collaboration - 400 Person Lung Cancer Detection Trial December 17th, 2014

SUNY Poly NanoCollege Faculty Member Selected as American Physical Society Fellow: SUNY Poly Associate Professor of Nanoscience Dr. Vincent LaBella Recognized for Significant Technological Innovations that Enable Interactive Learning December 17th, 2014

Switching to spintronics: Berkeley Lab reports on electric field switching of ferromagnetism at room temp December 17th, 2014

ORNL microscopy pencils patterns in polymers at the nanoscale December 17th, 2014

Possible Futures

A novel method for identifying the body’s ‘noisiest’ networks November 19th, 2014

Researchers discern the shapes of high-order Brownian motions November 17th, 2014

VDMA Electronics Production Equipment: Growth track for 2014 and 2015 confirmed: Business climate survey shows robust industry sector November 14th, 2014

Open Materials Development Will Be Key for HP's Success in 3D Printing: HP can make a big splash in 3D printing, but it needs to shore up technology claims and avoid the temptation of the razor/razor blade business model in order to flourish November 11th, 2014

Nanomedicine

Creation of 'Rocker' protein opens way for new smart molecules in medicine, other fields December 18th, 2014

Iranian Researchers Produce Electrical Pieces Usable in Human Body December 18th, 2014

Unraveling the light of fireflies December 17th, 2014

First Home-Made Edible Herbal Nanodrug Presented to Pharmacies across Iran December 17th, 2014

Discoveries

Creation of 'Rocker' protein opens way for new smart molecules in medicine, other fields December 18th, 2014

How does enzymatic pretreatment affect the nanostructure and reaction space of lignocellulosic biomass? December 18th, 2014

Iranian Scientists Use Nanotechnology to Increase Power, Energy of Supercapacitors December 18th, 2014

Iranian Researchers Produce Electrical Pieces Usable in Human Body December 18th, 2014

Materials/Metamaterials

ORNL microscopy pencils patterns in polymers at the nanoscale December 17th, 2014

Pb islands in a sea of graphene magnetise the material of the future December 16th, 2014

Graphene Applied in Production of Recyclable Electrodes December 13th, 2014

A golden thread through the labyrinth of nanomaterials December 12th, 2014

Announcements

Creation of 'Rocker' protein opens way for new smart molecules in medicine, other fields December 18th, 2014

How does enzymatic pretreatment affect the nanostructure and reaction space of lignocellulosic biomass? December 18th, 2014

Silicon Valley-Based Foresight Valuation Launches STR-IP™, a New Initiative for Startups to Discover the Value of Their Intellectual Property December 18th, 2014

Iranian Scientists Use Nanotechnology to Increase Power, Energy of Supercapacitors December 18th, 2014

Military

UCLA engineers first to detect and measure individual DNA molecules using smartphone microscope December 15th, 2014

Nanoshaping method points to future manufacturing technology December 11th, 2014

Stacking two-dimensional materials may lower cost of semiconductor devices December 11th, 2014

Industrial Nanotech, Inc. Expands Government and Defense Projects December 10th, 2014

Environment

Nanoparticles Prove Effective in Removing Phosphor from Calcareous Soil December 10th, 2014

Detecting gases wirelessly and cheaply: New sensor can transmit information on hazardous chemicals or food spoilage to a smartphone December 8th, 2014

Nanocatalysts Can Reduce Pollution Caused by Diesel Engines December 4th, 2014

Green meets nano: Scientists at TU Darmstadt create multifunctional nanotubes using nontoxic materials December 3rd, 2014

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE