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Ultra-Thin Solar Cells Can Be Bent Around A Pencil (computerworld.com.au)
angry tapir quotes a report from Computerworld: Scientists in South Korea have developed solar cells thin enough they can be bent around a pencil. The cells could help usher in the use of solar energy in small portable gadgets where space is at a premium. The cells are fabricated onto a flexible substrate that is just a micrometer thick -- one-half to one-quarter the thickness of other "thin" solar cells and hundreds of times thinner than conventional cells. [The team at the Gwangju Institute of Science and Technology in South Korea managed to reduce the thickness by directly attaching the cells to the substrate without the use of an adhesive. They were stamped onto the substrate and then cold welded, a process that binds two materials together through pressure, not heat. The scientists tested the cells and discovered they can almost be folded in half -- wrapped around a radius as small as 1.4 millimeters. A paper describing the work was published on Monday in Applied Physics Letters, a journal of the American Institute of Physics.]
I don't know why they went for the pencil example. Bendable solar cells seems like something you can have large areas of on your clothes.
And [dressing with solar cells] as long as they don't fail and set up in fire the dress...
Seriously, there is so many cases where dressing "gadgets" and "electrical thingies" near your skin is a so horrible idea...
Hence, the "pencil" example they used.
These would go great on electric cars. They wouldn't be enough to charge the batteries for putting the car in motion, but they would be enough to power sensors, displays, entertainment systems.
And cars stay out in the sun a whole lot of time.
Generated electricity could be used to zap you, so that you walk faster and do not jam up sidewalks.
Reading comprehension? 100 micrometers is just 1/10 millimeter.
Know the truth, there is no pencil.
~.~
I'm a peripheral visionary.
the pencil is used as an example because everyone can picture how tight the bend radius is...
Donald 'Duck' Dunn: We had a band powerful enough to turn goat piss into gasoline.
This is huge news for those of us that suffer from arthritis. No more struggling with those ridiculously thin pencils! Freedom at last!
Garry Knight
. . . like cost and durability ? If they are thin and flexible but degrade or fail easily (or are temperature sensitive, or the substrate breaks down under prolonged UV exposure, for example. . .) then it's only a nifty tech demonstrator.
Likewise, if the cost per watt is an order of magnitude higher than other, less-flexible technologies.
It's a complicated balancing act, and articles like this simply don't give much more information than a press release. Neat Tech ? Sure. Usable Tech ? Insufficient information. . .
The whole point of bendability is not that people are going to start wearing solar cells on their clothing (though we could see "charging hats" for hikers), but that it becomes practical to stick cells directly onto objects that flex slightly in use, like shingles. Solar shingles could make rooftop PV a default standard for new construction.
The trouble is that the solar cells only have a single direction of flexibility; as such, they cannot be applied to compound surfaces. I would like to see panels that can be applied to an aerodynamic surface, like that of a velomobile.
Still more important though, is to focus on weight, efficiency, and cost. To get about 300W I still need close to 6 square feet of panel. Further, even a lightweight panel system weighs over ten pounds.
Yes, an electric assist touring bicycle is avery special purpose; but, it is an example of achievable solar transportation. Further, as it is is my project, it is a application that interests me (I expect to be cross country ready by next summer).
It won't. If you laid in the direct noon sun with the bulk of your body pointed directly at it- maybe. But that sounds terrible.
Having it wrapped around a pencil certainly seems like a poor way to use a solar cell.
From the article, these are composed of thousands of GaAS micro-cells. Each cell is about 15% efficent. However, they appear to be spaced far enough apart to cover only about 1/4 of the area. That makes the array 3.75% efficent at best. Maybe future work can move them closer together.
And it's patented.
I've held them in my hand, at the UW CEI conference on campus.
-- Tigger warning: This post may contain tiggers! --
"They were stamped onto the substrate and then cold welded, a process that binds two materials together through pressure, not heat."
So, heat is a localized-effect of the pressure which eventually binds the two materials.
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