Capturing Solar Power With Antennae 190
necro81 writes "Researchers at the University of Missouri and the Idaho National Laboratory have demonstrated a new method of capturing solar power. Rather than using semiconductors to capture photons of sunlight, they fabricated small coiled antennae (several um square) that resonate with the wave nature of light. The antennae are tuned towards midrange infrared light (5-10 um), which is abundant on our cozy-warm Earth — even at night. They also demonstrated a way to imprint these coils on a substrate, like how CDs or vinyl records are produced, but could be scaled to roll-to-roll mass production. The usual caveat applies: it may be 5-10 years until this could hit the market."
Antennas (Score:5, Informative)
Re:Slow down and THINK before you use these. (Score:-1, Informative)
http://en.wikipedia.org/wiki/Chiropractic_education [wikipedia.org]
Beware (Score:1, Informative)
Re:Most important point not in summary (Score:5, Informative)
I think you see the problem - I *am* in a related field and I certainly don't know of any practical or efficient way to rectify it. I can think of absurdly inefficient ways, but we already have a bunch of those.
Re:Slow down and THINK before you use these. (Score:2, Informative)
Doctor of Chiropractic (DC) are indeed doctors. http://en.wikipedia.org/wiki/Chiropractic_education [wikipedia.org]
But not medical doctors. Considering the subject at hand was medical, all reputation is out the window.
Re:Slow down and THINK before you use these. (Score:2, Informative)
Yup, the correct term is "Doctor of Chiropractic," though I'm sure that's not what you actually meant.
No, it's not an MD. The term "doctor" is fairly general, and used in a wide manner to mean people other than those who can prescribe controlled substances or perform surgery.
Re:How hard can it be ... (Score:4, Informative)
Unobtainum diodes (Score:5, Informative)
What are they using to rectify the signal to convert to DC?
Unobtainum diodes. They don't actually know how to do that.
Terahertz diodes do exist [vadiodes.com]. Low-cost, high-efficiency, integrated terahertz diodes, no. But as work proceeds on terahertz electronics, someone may solve that problem. Each nanoantenna needs its own nanodiode, so the diodes have to be fabricated on the substrate with the antenna, which complicates the fab problem. The enthusiasm about roll-to-roll low cost fabrication in the article is premature. We'll probably see this working first on a wafer, and it may not be cheap.
Even if it's expensive, there's an initial market for satellite power panels. The performance improvement would be worth it.
Re:Unobtainum diodes (Score:5, Informative)
I've bought some 300Ghz diodes from Virginia Diodes. Worked great, but $7K each as I remember......
Here they need more like 100 THz. Might be possible with some sort of nonlinear optical material, but the fields are probably much too low.
Even if this whole scheme does work, its not clear it is any better than a conventional solar cell - they are quite efficient for narrow-band radiation right above their bandgap. You can stack different band-gap solar cells to get a quite efficient stack, but it doesn't make economic sense - sunlight is free, its the solar cells that cost money......
Bug antennae (Score:4, Informative)
Antennae are for bugs.
Funny you should mention that.
Apparently insects have similar antenna systems in their antennae to detect pheromones by their infrared signature. Also electret excitation structures attached other antenna structures to emit tuned infrared when pumped by grooming.
Here's one reference [sciencedirect.com].