Thursday, April 28, 2011

MIT's genetically modified viruses boost solar-cell efficiency by herding nanotubes


The wizards of MIT have done it again. Having checked artificial leaves and Operabots off the to-do list, they've moved on to improving the efficiency of solar cells. Their technique combines a genetically modified version of the M13 virus with carbon nanotubes, which have already been shown to increase efficiency. Unfortunately, some nanotubes enhance solar cell performance, while others inhibit it - and both types tend to clump together, negating their benefits. The modified M13 virus, however, can separate the two types as well as prevent clumping; we've seen similar use of the Tobacco mosaic virus to build better electrodes. Adding virus-built structures to dye-sensitized solar cells increased power conversion efficiency by almost one-third and, with only one additional step in the manufacturing process required, the new approach could be rapidly taken up by existing production facilities. MIT: proving once again that viruses are good for more than just smiting your enemies.

MIT's genetically modified viruses boost solar-cell efficiency by herding nanotubes originally appeared on Engadget on Wed, 27 Apr 2011 19:17:00 EDT. Please see our terms for use of feeds.

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Thursday, April 14, 2011

Latest Energy Breakthrough Threatens the Entire Existence of Solar Panels [Energy]


Latest Energy Breakthrough Threatens the Entire Existence of Solar PanelsUpending a theory of physics maintained for over a century, researchers at the University of Michigan have discovered that magnetic fields coming from light waves are 100 million times stronger than previously believed, creating new possibilities for harvesting solar power.

According to PhysOrg, this discovery came about when researchers ran a light source through a non-electric material:

Light has electric and magnetic components. Until now, scientists thought the effects of the magnetic field were so weak that they could be ignored. What Rand and his colleagues found is that at the right intensity, when light is traveling through a material that does not conduct electricity, the light field can generate magnetic effects that are 100 million times stronger than previously expected. Under these circumstances, the magnetic effects develop strength equivalent to a strong electric effect.

With current technology, the light has to be focused at an intensity of 10 million watts per centimeter squared, which is far stronger than natural intensity of the sun. However they're working with materials that will allow less intense light sources to produce energy (they're currently working with lasers).

The researchers believe that this breakthrough could lead to the development of an "optical battery," that doesn't use semiconductors, and doesn't need to absorb the light (which gives off heat during the process). Meaning this technology could be cheaper and more efficient. They believe that with a bit more research and better materials, 10% efficiency can be attained, which is the current percentage for commercial-grade panels. [PhysOrg]

Photo Credit: Flickr/Pixor


Sunday, April 3, 2011

Algae Could Be Key to Cleaning Up Nuclear Accident Sites


C. moniliferum, Crystallizing Strontium Minna R. Krejci et al. via CHEMSUSCHEM

Algae can secrete biofuels and pump out biologic drugs, and now researchers think it could help clean up radioactive accidents like the one unfolding at Japan's Fukushima nuclear facility. A Northwestern University researcher has identified a certain kind of common algae, known as Closterium moniliferum, that has a unique penchant for sequestering strontium into crystals, a trick that could help remove the dangerous radioactive isotope strontium-90 from the environment.

Strontium-90 is particularly hazardous because of its similarity to calcium. Because the two atoms share similar atomic properties, radioactive strontium can end up getting into the same places calcium can, like milk, bones, bone marrow, and blood. But strontium-90 isn't a dominant element in reactor waste--there is usually billions of times more harmless calcium than strontium in a nuclear spill--so being able to separate the two is critical for quick and efficient cleanup.

That's where C. moniliferum comes in. The algae's real interest is barium, but because a strontium atom is somewhere between calcium and barium in properties and size the algae happily vacuums up and crystallizes the strontium as well. But critically, it leaves calcium behind, meaning cleanup efforts don't end up sequestering a bunch of harmless calcium along with the dangerous strontium. And because the algae are really hunting for barium, the researchers think it's possible to seed a radioactive site with a small amount of barium to accelerate the entire process.

That saves both time and money, and in the midst of a massive disaster cleanup effort like the ongoing one in Japan, both time and money are extremely valuable. For their part, the algae waste little of either--they are easy to culture and begin to precipitate crystals of strontium within a half hour of contact. Strafe a stricken nuclear site with the tiny organisms, and you could have them hunting and sequestering strontium in a matter of minutes.