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Invisible Solar Nano Cells Promise Clean Energy
Posted by
samzenpus
on Wed Oct 17, 2007 07:26 PM
from the that-covers-all-the-buzzwords dept.
from the that-covers-all-the-buzzwords dept.
An anonymous reader writes "ZDNet is reporting that Harvard scientists have developed a silicon nanowire 200 hundred times thinner than a human hair that crank out up to 200 picowatts. Charles Leiber from Harvard University, who devised the technology with colleagues, is quoted: "An individual nanoelectronic device will indeed consume very little power, but to do something interesting will require many interconnected devices and thus the power requirement — even for nanosystems — can be a challenge". Conventional sources, he added, are "bulky, non-renewable and expensive" by comparison."
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Submission: Invisible solar nano-cells promise clean energy by Anonymous Coward
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If I had a nickle.... (Score:1, Funny)
a side product of balding hair research (Score:4, Funny)
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Localizers (Score:4, Interesting)
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Nope. I tend to avoid books by illiterates who need five words to say "height"
In other countries... (Score:1)
Same theory pretty much. Let me know when they're around again because I need some cookies from those fuckers in the goddamn tree.
An obvious question? (Score:5, Funny)
Erm, how bright is the inside of a body!?
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Gaah where's my fork (--recent eye surgery patient)
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(Yes, I'm ashamed of thinking this...)
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It's being developed for people that live near Chernobyl. Kind of like the X Ray film that you just have to stand next to for five minutes and the lead lined shorts that are a fashionable item in Kiev.
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Sincerely,
Hannibal Lecter
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Hold your hand up to a lamp. Notice the light coming through it. Very diffused, but clearly quite a bit there.
Of course if you move the nanowires out to the skin level the transparency of the body - even with a heavily-pigmented skin - is no longer an issue.
However, given the enorm
I Hate Science Reporting (Score:5, Insightful)
I hate science reporting. It's also nice to know the editors aren't doing their jobs (ZDNet, I don't blame /.). What is a single strand? Is that 10mm long? 10cm? 1m? There is a big difference between those three. The summary just chops that sentence up worse. And why do they always use human hair as a comparison? Who's hair is that? Some people have very thin hair. For some people it is quite a bit thicker. If you are comparing it to the average, you should include that word. Also are we talking theoretical maximum or a practical estimation under normal daylight conditions?
It's great to know this generates 200 picowatts per something. How about comparing it to a normal production solar cell. I'm glad you can make it thin, but it must need some kind of support structure to survive, so how much thicker does it need to be so it is actually useful? After all, the silicon part of a solar cell is just a fraction of it's thickness.
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In the case where a reasonable person would understand that "average" is meant, then "average" is just a useless word cluttering up the sentence. Its presence or omission is best left to the writer, subject to the needs of the surrounding text and the work as a whole.
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These way-out-there Geeky-Geeks often have a hard rationalizing value comparisons that the closer to average type Geeks might consider common sense.
Re:I Hate Science Reporting (Score:4, Insightful)
I mean the possibilities are endless depending on the properties of the stuff. It is made out is silicon it is small, and it produces power. It should be Usable in a lot of ways.
Parent
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I'm guessing it could be made into a larger fiber, but I don't think it would make any sense to do so.
Since this is solar power, any of the nano-fibers that are inside the larger fiber wouldn't generate any power since they wouldn't receive any light. Also, I'm guessing that there would be problems "lining up" the different layers of the nano-fibers resulting in some sort of short in the system. Another question I have is, dealing with this small scale, does the internal resistance in the wire cause scal
Re:I Hate Science Reporting (Score:5, Insightful)
Your point about leaving off the length is a good one. Science journalists don't seem to understand enough about what they're covering to know which points are important or which claims are plausible.
Parent
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Which strand? The anchor strands one can clearly see or the capture strands? Which species of spider? And of course, I live in an area where the only spiders are taratulas you insensitive clod!
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I see... the nature doesn't provide enough precision (or nothing at all). Then I propose strands of industrial artificial material(such as, i.e, lycra, used for ladies stockings) assorted by their width. You can have samples made into microscope slides (you can have free strands too), students can see them through wi
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Re:I Hate Science Reporting (Score:5, Funny)
Parent
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I wonder (Score:5, Interesting)
Then again maybe I'm just rambling on after approaching the 40th consecutive waking hour... It'd be nice to know.
Re:I wonder (Score:5, Interesting)
Not usually true. Plants and animals have plenty of other concerns, such as the efficient storage thereof, combating predators, reproducing, etc., any one of which could take precedence over obtaining energy. Is fat the most economical storage medium? It's pretty good, but other factors come into play: it's not toxic to the body, it's pliable, which permits relatively free movement, it's a good insulator, and it provides protection to bones and internal organs (any of which may or may not be an evolutionary side effect). Natural selection is about favoring the most competitive in a particular environment, and obtaining the most energy, while ignoring other factors, is not always the best strategy. A design that extracts more energy from sunlight than pine needles might be more prone to wind damage, pests, molds, fungus, etc. Even if an organism is more efficient at extracting energy than its competitors, that's no guarantee that its the *most* efficient possible design, just that it was good enough.
Additionally, what we're primarily concerned with is electromagnetic energy. There are always losses in any conversion, and if we convert the sunlight into chemical energy, then back into electromagnetic energy, we're guaranteeing more losses than if we can harness/store the sunlight directly. That's why it's often more efficient to use net metering rather than off-grid battery storage alone. Many people opt to include batteries in their solar systems, but that's typically for the purpose of grid independence and/or backup power. Of course there are losses inherent in converting DC to AC, so that must be considered as well. Overall, the more directly you can transfer the power from the source to the load, the more efficient that transition will be.
I'm not a biologist, but I did stay at a Holiday Inn last night.
Parent
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Unfortunately comparing the efficiency of plants to this wire thing isn't that simple. Chloroplasts have lots of internal complexes(Thylakoid disks) full of organized protein structures th
Wait a minute, I'm confused (Score:2, Funny)
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-nano
-invisible solar cell (Yeah, light ignores it, but is also absorbed by it.)
-clean energy
(Btw just got back from a
Some assembly required (Score:2)
We all want to look for macro-applications right away, but it seems pretty obvious that this is meant for the micro.
I'm not going to stoop to doing the math (*ahem*), but I'm imagining we're not talking about a huge efficiency gain over high-end conventional sources.
Not to mention the "assembly barrier" to something like this. You though installing that modchip to put Fedora on your XBox was hard, that was just a few fiddly wires. Imagine some poor Chinese factory slave-labor dude with his soldering iron an
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Anyways, this is one job that I wouldn't complain if a robot took from us.
Hey.... (Score:5, Funny)
I WON SLASHDOT BINGO!!!
TFA was for Dora the Explorer club, and not /. (Score:2, Informative)
The journalist is either completely clueless or trying to make it comprehensible for kindergarten. The result is so wrong and incomprehensible that it is worthless:
200 hundred? (Score:3)
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Of course in Europe a billion is one million million (bi-million). Thats why people say one thousand million - because it's completely different.
Fixed that for you. The "US" usage of billion is more common worldwide, and increasingly more so. It keeps us all from having to deviate from the systematic approach. A trillion isn't a million million million, is it?
It gets really confusing when you're talking in powers of higher than that. A novemdecillion, for instance, is easy to calculate - that's nove - 9, dec-10, so 19 groups of "000" after the first. The formula for understanding the number is more complex under the french system, which is why
How does this work (Score:2)
Then it isn't invisible, is it?
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Wow! (Score:2)
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Actually, when you come to think of it that's pretty good for such a nanostructure. But I wonder if stringing such structures together in a scale that would permit reasonably measurable current flow wouldn't generate enough heat to let the magic smoke out at ambient STP? Is there a point of diminishing returns, or could they perhaps be partially embedded in a matrix of something th
Definition of PicoWatt (Score:2)
Lets do some questimating! An average hair is around 50 micrometers thick, so lets guess they are talking about a 0.25 micrometer thick wire. Lets guess they are talking about a 10 cm long piece. Plugging the numbers and their stated power yields a whopping 0.008 watts/squaremeter. A cheap 6% efficient solar cell in bright sunlight (1 sol = 1000watts/sqmeter) gives you 60
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1 pico watt is still 1.6e8 eV/s. See, a huge number. A hypotetical nano-assembly powered by that could ionize near 6.5e7 hydrogen atoms per second, and, while 250nm is a bit big for such application, you could still put 4e6 such machines in a centimeter, leading to 26e13 atoms/(s cm).
Of course, everything depends on how long is the cell. You got 10cm from nowhere, it would even be hard to make it that long. If you are right about the length, it is useless. But if its length is 4 times bigger than the width
What? (Score:2)
]{
A furry battery charger? (Score:2, Insightful)
Let's see, we've got nanowire that's "Thinner than a human hair", and generates 200 picowatts of electricity. So, if we use these things tethered at one end and free to sway loose at the other, we have a mat of electric-generating "fur". Fuzzy satellites? Implant into the human scalp (To cover those bald spots) and you could power your cybernetic implants. Self-powering Electro-Luminescent wire (Charges when off)?
Weave these things into a cloth, and we could have spaceships with a power-generating solar sa
Very silly idea (Score:2)
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Who is eyeing this.. (Score:2)
DHCP pools = more than one person editing (Score:2)
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