We noticed you're browsing in private or incognito mode.

To continue reading this article, please exit incognito mode or log in.

Not an Insider? Subscribe now for unlimited access to online articles.

From the Labs: Materials

New publications, experiments and breakthroughs in materials–and what they mean.

Tiny Lasers
The smallest laser ever could find uses in future computers.

Nano laser: These spheres, which are 44 nanometers in diameter, are made of gold coated with dye and silica. Each is a laser.

Source: “Demonstration of a spaser-based nanolaser”
Mikhail A. Noginov et al.
460: 1110-1112

This story is part of our November/December 2009 Issue
See the rest of the issue

Results: A new laser devised by researchers at Norfolk State University, Purdue, and Cornell is the smallest ever made: it consists of a nanoparticle just 44 nanometers in diameter. It can emit both photons and plasmons, which are waves that travel along the surface of metals.

Why it matters: The research is the first demonstration of a spaser, a device that some physicists believe will form the basis of future optical computers. Such computers have the potential to be much faster than today’s electronics, but current optical devices are bulky because photons are difficult to confine. Light in the form of plasmons can be confined to much tighter spaces, allowing for very fast, compact chips. Though researchers have previously made devices that can rout plasmons on chips, this spaser is the first device that can generate and amplify them.

Methods: To make the laser, the researchers coated a gold nanosphere with a layer of silica that’s embedded with dye. The gold provides the medium where the plasmons form; in the dyed silica layer, plasmons excited by light from a pumping laser are amplified, much as photons are amplified in the mirrored cavity of a conventional laser. The amplified plasmons then escape to travel along a metal surface, or they can be converted to photons so that the device emits a laser light. Either way, the device produces waves with the frequency of green light.

Next steps: The spasers could be improved by modifying them to emit different wavelengths. Spasers that work in the infrared, for example, might be useful for telecommunications.

Cool Fuel Cells
Improved materials make solid-oxide fuel cells more practical.

Source: “Impact of Anode Microstructure on Solid Oxide Fuel Cells”
Toshio Suzuki et al.
325: 852-855

Results: Japanese researchers lowered the operating temperature of solid-oxide fuel cells by changing the structure of their electrode materials. They improved the power output of the cells at 600 °C by an order of magnitude.

Why it matters: Solid-oxide fuel cells can efficiently convert a variety of fuels, such as hydrogen and diesel, into electricity. But because they typically operate at temperatures above 700 °C, they require expensive materials, wear out relatively quickly, and are limited to stationary applications. Compared with other approaches to lowering the operating temperature of fuel cells, the new method has the advantage of using conventional materials that are relatively inexpensive. The new fuel cells could eventually be useful as auxiliary power sources to extend the range of electric vehicles, among other applications.

Methods: The researchers used established processes to fabricate tubular fuel cells 1.9 millimeters in diameter. To produce anodes with different structures, they heat-treated the tubes–which consist of a zirconia-based ceramic and a nickel-oxide mixture–at three temperatures lower than those ordinarily used in fuel-cell production. The resulting anodes were unusually porous, which proved to increase the performance of fuel cells based on them.

Next steps: The researchers established that they can bundle the microtubular fuel cells, but they need to develop ways to turn the bundles into modules that generate enough power for commercial applications.

Become an MIT Technology Review Insider for in-depth analysis and unparalleled perspective.

Subscribe today

Uh oh–you've read all of your free articles for this month.

Insider Premium
$179.95/yr US PRICE

Want more award-winning journalism? Subscribe to Insider Premium.
  • Insider Premium {! insider.prices.premium !}*

    {! insider.display.menuOptionsLabel !}

    Our award winning magazine, unlimited access to our story archive, special discounts to MIT Technology Review Events, and exclusive content.

    See details+

    What's Included

    Bimonthly magazine delivery and unlimited 24/7 access to MIT Technology Review’s website

    The Download: our daily newsletter of what's important in technology and innovation

    Access to the magazine PDF archive—thousands of articles going back to 1899 at your fingertips

    Special discounts to select partner offerings

    Discount to MIT Technology Review events

    Ad-free web experience

    First Look: exclusive early access to important stories, before they’re available to anyone else

    Insider Conversations: listen in on in-depth calls between our editors and today’s thought leaders

You've read all of your free articles this month. This is your last free article this month. You've read of free articles this month. or  for unlimited online access.