Laser technology creates new forms of metal and enhances aircraft performance

Washington, July 16 (ANI): A team of scientists is using laser light technology to create new forms of metal and enhance aircraft performance.

The laser light technology is being used by AFOSR (Air Force Office of Scientific Research) funded researchers at the University of Rochester to help the military create new forms of metal that may guide, attract and repel liquids and cool small electronic devices.

Dr. Chunlei Guo and his team of researchers for the project discovered a way to transform a shiny piece of metal into one that is pitch black, not by paint, but by using incredibly intense bursts of laser light.

The black metal created, absorbs all radiation that shines upon it.

“With the creation of the black metal, an entirely new class of material becomes available to us, which may open up a whole new horizon for various applications,” said Guo.

“To do this, we looked at the reverse process of light absorption or light radiation and transformed the incandescent lamp into a bulb that glows twice as brightly as a regular light source, while consuming the same amount of energy,” Guo added.

The key to creating this super-filament is an ultra-brief, ultra-intense beam of light called a femtosecond laser pulse.

The laser burst lasts only a few quadrillionths of a second.

That intense blast forces the surface of the metal to form nano-structures and micro-structures that dramatically alter how efficiently light can radiate from the filament.

In addition to increasing the brightness of a bulb, Guo’s process can be used to tune the color of the light as well.

In addition to this research, Guo and his team have been working on creating technology that may enable the Air Force to create an additional kind of metal.

They are able to do this by using the femtosecond laser once again to alter the surface of metal and create unique nano- and micro-scale structures on the metal.

The unique nano-structures which are created from the laser affect the way liquid molecules interact with metal molecules.

The liquid spreads out over the metal because the nano-structures attach themselves to the liquid’s molecules more readily than the liquid’s molecules bond to each other.

The end result is the formation of a new kind of metal that can cool the plane’s electronic brain and heat pumps and allow the craft to retain dominance over any enemy that is also in flight. (ANI)

New surface treatment boosts efficiency of photovoltaic cells

Washington, March 25 (ANI): Researchers at the Georgia Institute of Technology have developed a surface treatment that boosts the light absorption of silicon photovoltaic cells in two complementary ways.

The surface treatment increases absorption both by trapping light in three-dimensional structures and by making the surfaces self-cleaning – allowing rain or dew to wash away the dust and dirt that can accumulate on photovoltaic arrays.

Because of its ability to make water bead up and roll off, the surface is classified as superhydrophobic.

“The more sunlight that goes into the photovoltaic cells and the less that reflects back, the higher the efficiency can be,” said C.P. Wong, Regents’ professor in Georgia Tech’s School of Materials Science and Engineering.

“Our simulations show that we can potentially increase the final efficiency of the cells by as much as two percent with this surface structure,” he added.

The silicon etching treatment mimics the superhydrophobic surface of the lotus leaf, which uses surface roughness at two different size scales to create high contact angles that encourage water from rain or condensation to bead up and run off.

As the water runs off, it carries with it any surface dust or dirt – which also doesn’t adhere because of the unique surface properties.

In the silicon surface treatment, the two-tier roughness – created with both micron- and nano-scale structures – works in the same way as the lotus leaf, minimizing contact between the water or dust and the surface, Wong noted.

“When a water droplet reaches the surface, it sits on top of this two-tier roughness and only about three percent of it is in contact with the silicon,” he explained.

“A normal silicon surface reflects a lot of the light that comes in, but by doing this texturing, the reflection is reduced to less than five percent,” said Dennis Hess, a professor in the Georgia Tech School of Chemical and Biomolecular Engineering.

“As much as 10 percent of the light that hits the cells is scattered because of dust and dirt of the surface. If you can keep the cells clean, in principle you can increase the efficiency. Even if you only improve this by a few percent, that could make a big difference,” he added.

According to Wong, even in desert areas where constant sunlight provides ideal conditions for photovoltaic arrays, nighttime dew should provide enough moisture to keep the cells clean. (ANI)