Last week EcoGeek stumbled across a little story about some little antennas that could, just maybe, revolutionize not just the solar industry, not just the energy industry, but the whole entire world.

Well, we thought there was a bigger story there than we could get from one press release, so we contacted the scientists behind the project and it turned out we were right. Dr. Steven Novack took some time to tell us about his nano-antenna (or has he calls them, nantenna) arrays, and some of their potential applications.

I was blown away.

The original article discussed how nantennas could be used as a solar panel that could beat all current efficiencies at a much lower cost. But it turns out that nanetennas have dozens of other uses, many fascinating for EcoGeeks. These include:

• Passive, energy-neutral cooling by converting infrared radiation into radiation that we don't feel as heat (like radio waves)
• Passive heating by turning radiation we don't feel as heat into infrared radiation
• Extremely efficient lighting by basically broadcasting photons from the nantennas. As it's basically the solar process in reverse (photons from electrons, instead of electrons from photons), this is just as feasible as the solar applications
• Passive heating or cooling within clothing
• Electricitiy production in clothing by harnessing our bodies' radiation.

Dr. Novack was kind enough to answer some of our questions. Keep on reading if you want to hear more about this fascinating technology, and where it's headed five, ten, and twenty years down the road.

EcoGeek: So tell me about your nano-antenna arrays.

Dr. Steven Novack: All antennas are very good at receiving and transmitting electromagnetic radiation. But the difficulty has been creating nantennas of the proper size to capture the wavelengths emitted by the sun. The ability to tune the antenna to the size of the wavelength is very important.

EG: Can you make these arrays pick up radiation throughout the sun's spectrum, or is it just one specific wavelength?

SN: We can do both; we're very good at tuning antennas to one specific frequency and very good at making them broadband.

However, INL is fairly new in this world of nanotechnology. Because of that, we're working to get a product out that would be easier for us to prototype. So we've selected a little bit longer wavelengths. As the technology progresses, we'll certainly be interested in moving that down to the visible range.

EG: Can you talk a bit about the materials that go into these new panels?

SN: Materials are fairly straightforward. We need some sort of substrate as a base, and we've chosen a plastic to keep costs low. We have a pattern that we stamp onto the plastic, and then we deposit certain kinds of metals. The metals have to have certain characteristics. For the research phase, we're focusing less on cost and more on the amount we know about them. The current prototype is being done with gold. The entire one foot by two foot sheet that we created used less than 60 cents of gold, but if we have to go to aluminum, copper, or silver, we could certainly do that.

EG: Right now there your nantenna array can't convert the energy it creates into a useful current. I've heard that you'll need another nano-electronic component to make that a possibility. Has there been progress in that area?

SN: A lot of scientists are working on nanoelectronics to support optical computing. There's been a lot of breakthroughs in the last year or so in terms of prototypes that can handle these types of currents. We have not yet attempted to integrate them into the array, but we're looking for strategic partners that can help us with that.

EG: So when you talk about mass production, how mass are we talking about?

SN: The manufacturing process is part of what we were recognized for in this year's Nano50 awards. We're pretty good at large-scale manufacturing, and we're hoping for roll-to-roll processing.

EG: Does this excite you more than just scientifically?

SN: This is probably one of the more socially significant projects that we've done. Obviously, with the world economy's need for cheap energy, we're hopefully going to make life better for everyone.That's definitely a driving force.

EG: So do you think about the environment as you work on this projects?

SN: When we think about manufacturing, we think about the materials and processes as well as the end result. The environment is a huge factor. We only look at stuff that fits our environmental criteria. There's no sense in trying to help the environment if the process creates a negative waste stream.

And then there's an overall concept of heat and entropy, and how much we waste our energy as heat.

Antennas that are good in receiving in an area are also very good at emitting in an area.

EG: So are you saying that these could be a light source as well as a light collector?

SN: There are some challenges to that concept that we're going to be working on. But with your imagination you can probably think of more applications than I can.

The first application I see is: "Here's a nice way to cool a room." The solar applications are probably more important, but we're a lot closer to that kind of passive temperature management.

EG: On that very exciting note, I'll just ask if you can think of any way to help our world stay sustainable.

SN: My personal hope is that we decrease world conflict by increasing availability of resources so that people can have a better life. There's a direct correlation there. And, of course, I'd love to see more emphasis put onto funding this type of work.

Comments (12)

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mr
written by Matthew J Banks , February 07, 2008

i have an eco friendly myspace page. on the right i have a link to a picasa web album where i've scanned my sketches but one of the drawings is for a nantenna or facsimile. i want you to see it and have it for the benefit of mankind. f-=well here's the link to the picture - live long and prosper.

http://tinyurl.com/2ztubh

interesting indeed...
written by Jane Porter , February 08, 2008

Thanks for highlighting this interesting technology.

We need all the different approaches we can get to fight off fossil fuels.

Looking forward to hearing more about this as the technology progresses.

thanks,

Jane

...
written by Mamie Cosco , February 08, 2008

The idea of cooling a room with nanoantennas reminds me of the need to increase availability of resources so people can have a better life.

I always say a prayer and drink to world peace.

Wavelength shifting?
written by Virgil , February 08, 2008

I'm kinda curious as to how this actually works at the molecular level. There are molecules and technologies that will increase the wavelength of electromagnetic radiation. For example, fluorescent dyes will accept light of a particular wavelength (say green) and emit light at a longer wavelength (say red). This is a lower energy emission than what was put in, because the longer wavelength light has lower energy.

As far as I know, the wavelength shifts achievable by such molecules are pretty small (on the order of a hundred nanometers maximum). It therefore seems implausible that you can shift wavelength by several hundreds or even thousands of nanometers, as would be required for example to turn light into heat or back again.

Of course, there's also the other issue that no-one has yet found a way to decrease wavelength (i.e. increase energy) in an efficient way. You can't just put in a low energy photon (like infra-red), and get a high energy photon (like visible light or x-rays) without some extra energy input. It can't simply be a 1:1 photon conversion process! It is thermodynamically impossible. Now, there is such thing as 2-photon or even 4-photon fluoresence, and that might be how this works. In that process, 2 photons of low energy (say 600nm) will excite the molecule at half-wavelength (i.e. 300nm) and it will emit at a longer wavelength than excited (say 400nM). However, the maximum efficiency achievable by this is 50%, because you need to put in 2 photons to get one out.

Unless this guy has figured out a way to make energy out of nowhere, call me a skeptic I don't buy all this resonance/vibration crap. How the hell do you put in low-energy photons and get out high energy photons? Where does the energy come from?

Did he say...
written by Eric , February 08, 2008

EG: On that very exciting note, I'll just ask if you can think of any way to help our world stay sustainable.

SN: My personal hope is that we decrease world suck by increasing availability of resources so that people can have a better life. There's a direct correlation there. And, of course, I'd love to see more emphasis put onto funding this type of work.

Energy from nowhere (and your chicks for
written by John , February 09, 2008

That low energy photon in, high energy photon out trick may sound like magic, but it doesn't necessarily violate energy conservation.

The conversion device is a mystery of course, but there are things like voltage doublers and hydraulic rams that convert high volume at low pressure into low volume at high pressure, no laws of physics violated. Perhaps the same thing can be done with photons...

Carpenter's Helper
written by davie , February 12, 2008

Hello Hank Green and All Others,

I came to your article via jb's sustainabledesignupdate website, thanks, John Barrie!

Having read and reread Farrington Daniels's book: Direct Use of the Sun's Energy, Revised 1974 many times, my first impression upon reading Hank Green's Ecogeek piece was : selective radiation coatings times quantum leap, then, as reading proceeded, it all reminded me of the heatpipe first encountered in Sci.Amer.magazine. A nanoscale heatpipe would have a minimum size of pipe sufficiently large to accomodate the requirements of the given working fluid which must pass through a transition from a vapor state to a liquid state and travel the length of the pipe by capillary action to complete a working cycle by being vaporized again by the heat input and passing the length of the pipe again, in the opposite direction, as a molecule of vapor at molecular speed. A heatpipe is able to conduct heat the length of the pipe at a far greater efficiency than the best of solid conductors.
What I imagined is that the nantenna is accomplishing a transfer and transformation of energy utilizing electrons in a role like a working fluid plays in a heat pipe, in so far as it goes between the recieving and emitting ends of the system. This might be wrong: the nantenna might be imagined as a single molecule that accepts the energy of electromagnetic energy on one end and emits a ray of some nearly equivalent or less energy out the other end--that is, without electrons flowing through some intermediary conducting medium. Of course the imaginable possibility exists that nantennas require some conveyance between the receiving and emitting which could be some plasma stuff like solar wind in a magnetic field,for all I do not know. All I really know is that sixty cents U.S. times 2 sq.ft. worth of gold with the possibility of substiting other metals albeit no doubt with trade-offable efficiencies, rings like an economically viable proposition to me. I for one will be trecking along the links and references to be learning more...the "mind blowing" as someone upstream put it, possibilities at least for sci fi are right there fo sho. Well, also, the Hank Green piece is getting a second read here now...
if you will excuse me, presently adding a new favorite..
davie

carpenter's helper
written by davie , February 13, 2008

Geez, what a horrid bit i left above. I do insist none the less, that this subject seems a wonder filled learning/teaching vehicle. In defense of my crappy bit above: Emphasis was on the Imagining, just for the hope of jogging someone into a better idea. Thanks for the free platform!

Davie

Just found out about you and I want to s
written by Rosa R. , April 26, 2008

I found this site today (April 26, 2008-Sat) by accidentally stumbling upon Yahoo!Green a few days ago! This is a very cool site! Thankyou Hank!! Great stories!!! and links!

-Rosa
(always a fan of the environment and making sure I take it upon myself to learn more and more, and be able to use that knowledge for the better!)

...
written by Rosa R. , April 26, 2008

I'd also like to thank Dr. Steven Novack at the Idaho National Laboratory and colleagues for making such a tremendous breakthrough!!!! Thankyou Hank chief geek for bringing us this incredible piece of news!!!! Love you both for both of your contributions to a better/smarter world!

Video on nanoantenna
written by Sara Prentice , June 11, 2008

At Idaho National Laboratory we have produced a video on the solar nanoantenna technology. You can view it at:

http://www.youtube.com/watch?v=9fuofnZM5eE

Not entirely true....
written by Katmandu , June 27, 2008

First off, he isn't a DR... he doesn't have a PhD - he has a Masters in Environmental Engineering. Did you ask if he can verify the existence of the nano antennas on that piece of gold sheet? He'd be lying if he says he can. Oh, and that nice image of the spiral antennas is courtesy of Univ. of Central Florida - it was THEIR work, not the lab's. Lastly, any real scientist would tell you that this is so far-fetched it is crazy AND it helps if you don't steal your colleague's ideas and life work in the process to create a name and buck for yourself, Dr. Novack!

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