Hey folks !
Have been around here following Mach engines, ENR microwave engines, Rossi stuff, etc,etc... and lots of follow-ups on Next Big Future topics.
Finally decided to register, because i would like to float some ideas we need for our NEA mining group over on Y*hoo groups.
The guys down at UofAZ have found a simple way to convert heat to electricity, and i would like to get a variation out into the public domain before someone patents it, for the good of all mankind, save the ecosphere, and all that.
And we really need a way to get rid of excess heat in the mining ships too!
The link for the discovery is here.
http://uanews.org/node/34382
This isn't a peltier model, but a path length change. Very simple, just need a conductor on the base to pull the charge off.
what i have been reading suggests that we can use this same effect in graphene to use a lower toxicity material to generate the same effect.
http://www.nature.com/nchem/journal/v3/ ... m.985.html
Since it is easier to put defects into graphene films, than to make perfect sheets, we should be able to create defects in a graphene film or nanotubes, to create isolated benzene chains in the laminate.
We are going to be using LOTS of PET sheeting (Mylar) for our mining operation, and would like to figure out a way to use this as conductors, scaffolding, and possibly as a generator too.
It appears using nanotowers, you can catch most of the eV coming in, not just visible wavelengths. If we can vapor deposition a layer of nanotowers right on to the surface of the ship, we could avoid having solar panels AND radiators sticking out at weird angles, shield occupants and electronics from solar wind, cosmic and maybe gamma rays, and have a PV type energy harvesting coating on the outside, with a heatsink for the inside.
'Nano-Manhattan' 3D solar cells boost efficiency (physorg.com) link busted.
and (will post paper another as comment, no link)
These nano towers can be tuned to whatever frequency you need by changing the spacing, and doping used. Would be great to have in the Van Allen belts - could shield the hardware and the wetware.
What do you think ?
The REAL thermo-electric effect. With variations ?
here is one of the nanotower papers, they describe a cheap and easy fab technique we can probably use on orbit.
Friday, July 16, 2010
Nanopillars that Trap More Light
The new design could lead to cheaper solar cells.
By Prachi Patel
A material with a novel nanostructure developed by researchers at the University of California, Berkeley could lead to lower-cost solar cells and light detectors. It absorbs light just as well as commercial thin-film solar cells but uses much less semiconductor material.
The new material consists of an array of nanopillars that are narrow at the top and thicker at the bottom. The narrow tops allow light to penetrate the array without reflecting off. The thicker bottom absorbs light so that it can be converted into electricity. The design absorbs 99 percent of visible light, compared to the 85 percent absorbed by an earlier design in which the nanopillars were the same thickness along their entire length. An ordinary flat film of the material would absorb only 15 percent of the light.
Structures such as nanowires, microwires, and nanopillars are excellent at trapping light, reducing the amount of semiconductor material needed, says Erik Garnett, a research fellow at Stanford University. Nanowires and nanopillars use half to a third as much of the semiconductor material required by thin-film solar cells made of materials such as cadmium telluride, and as little as 1 percent of the material used in crystalline silicon cells, he says. These structures also make it easier to extract charge from the material. Overall, these improvements could make solar cheaper. "Reducing material costs while achieving the same amount of light absorption and hence efficiency is very important for solar cells," says Shanhui Fan, an electrical engineering professor at Stanford.
Many nanostructrued materials have complex designs and require cumbersome fabrication methods to deposit multiple layers, says Ali Javey, an electrical engineering and computer science professor at UC Berkeley who is leading the new work, which is posted in the journal Nano Letters. He says the technique to grow the nanopillars is relatively simple and low-cost.
The researchers make nanopillars two micrometers high, with bases that are 130 nanometers in diameter and tips that are 60 nanometers in diameter. They start by creating a mold for the pores in a 2.5-millimeter-thick aluminum foil. First they anodize the film to create an arrangement of pores that are 60 nanometers wide and one micrometer deep long. They then expose the foil to phosphoric acid to broaden the pores to 130 nanometers--the longer the foil is exposed to the acid, the broader the pores get. Anodizing the film again makes the existing pores one micrometer deeper, and this additional length has the original 60-nanometer diameter. Trace amounts of gold are then deposited in these pores as a catalyst to grow crystals of semiconductor material--in this case germanium, which is good for photo detectors--inside each pore. Finally, some of the aluminum is etched away, leaving behind an array of germanium nanopillars embedded in an aluminum oxide membrane
Javey says that this method of making nanopillars of varying diameters and shapes is simple compared to other approaches, which involve a complicated layer-by-layer assembly of materials, and complex materials that combine wires with metal nanoparticles.
Garnett agrees that Javey's method could be cheap, but says it's still too early to know if the method can translate to a large-scale manufacturing process. "The most exciting thing is proof that nanostructuring can dramatically increase absorption," he says.
By tweaking the arrangement of the pillars, it could be possible to make materials that absorb longer infrared wavelengths of light, which would be useful for making efficient, cheap infrared light detectors. Since submitting the Nano Letters paper, the researchers have also used the technique to make nanopillars of cadmium telluride, a material better suited for solar cells than germanium.
Copyright Technology Review 2010.
Friday, July 16, 2010
Nanopillars that Trap More Light
The new design could lead to cheaper solar cells.
By Prachi Patel
A material with a novel nanostructure developed by researchers at the University of California, Berkeley could lead to lower-cost solar cells and light detectors. It absorbs light just as well as commercial thin-film solar cells but uses much less semiconductor material.
The new material consists of an array of nanopillars that are narrow at the top and thicker at the bottom. The narrow tops allow light to penetrate the array without reflecting off. The thicker bottom absorbs light so that it can be converted into electricity. The design absorbs 99 percent of visible light, compared to the 85 percent absorbed by an earlier design in which the nanopillars were the same thickness along their entire length. An ordinary flat film of the material would absorb only 15 percent of the light.
Structures such as nanowires, microwires, and nanopillars are excellent at trapping light, reducing the amount of semiconductor material needed, says Erik Garnett, a research fellow at Stanford University. Nanowires and nanopillars use half to a third as much of the semiconductor material required by thin-film solar cells made of materials such as cadmium telluride, and as little as 1 percent of the material used in crystalline silicon cells, he says. These structures also make it easier to extract charge from the material. Overall, these improvements could make solar cheaper. "Reducing material costs while achieving the same amount of light absorption and hence efficiency is very important for solar cells," says Shanhui Fan, an electrical engineering professor at Stanford.
Many nanostructrued materials have complex designs and require cumbersome fabrication methods to deposit multiple layers, says Ali Javey, an electrical engineering and computer science professor at UC Berkeley who is leading the new work, which is posted in the journal Nano Letters. He says the technique to grow the nanopillars is relatively simple and low-cost.
The researchers make nanopillars two micrometers high, with bases that are 130 nanometers in diameter and tips that are 60 nanometers in diameter. They start by creating a mold for the pores in a 2.5-millimeter-thick aluminum foil. First they anodize the film to create an arrangement of pores that are 60 nanometers wide and one micrometer deep long. They then expose the foil to phosphoric acid to broaden the pores to 130 nanometers--the longer the foil is exposed to the acid, the broader the pores get. Anodizing the film again makes the existing pores one micrometer deeper, and this additional length has the original 60-nanometer diameter. Trace amounts of gold are then deposited in these pores as a catalyst to grow crystals of semiconductor material--in this case germanium, which is good for photo detectors--inside each pore. Finally, some of the aluminum is etched away, leaving behind an array of germanium nanopillars embedded in an aluminum oxide membrane
Javey says that this method of making nanopillars of varying diameters and shapes is simple compared to other approaches, which involve a complicated layer-by-layer assembly of materials, and complex materials that combine wires with metal nanoparticles.
Garnett agrees that Javey's method could be cheap, but says it's still too early to know if the method can translate to a large-scale manufacturing process. "The most exciting thing is proof that nanostructuring can dramatically increase absorption," he says.
By tweaking the arrangement of the pillars, it could be possible to make materials that absorb longer infrared wavelengths of light, which would be useful for making efficient, cheap infrared light detectors. Since submitting the Nano Letters paper, the researchers have also used the technique to make nanopillars of cadmium telluride, a material better suited for solar cells than germanium.
Copyright Technology Review 2010.
I have been in direct contact with Justin Bergfield from October 2010.
The research is interesting, but no real progress has been made until now, or at least no real progress that he fells to share with the rest of the world.
You have also to consider that this is just a theretical model for now, and no real experimental device has been manufactured until now. Reality might be pretty different than the theoretical model.
You can read the old thread here:
viewtopic.php?t=2632
I will send him another e-mail asking if they made any progress to date in manufacturing the experimental device.
The research is interesting, but no real progress has been made until now, or at least no real progress that he fells to share with the rest of the world.
You have also to consider that this is just a theretical model for now, and no real experimental device has been manufactured until now. Reality might be pretty different than the theoretical model.
You can read the old thread here:
viewtopic.php?t=2632
I will send him another e-mail asking if they made any progress to date in manufacturing the experimental device.
Justin was kind enough to find the time to quikly reply to my e-mail, this is the most important part:
It's good to see that he is moving forward, hopefully there could be some interesting news in the coming months to prove or disprove the theoretical model.We are currently working with a number of companies to test our concept in the lab and/or make an actual device.
These efforts are still on going and in the meantime I've been working on several other molecular thermoelectric papers which I hope will appear in the next few months.
Best regards,
Justin
Sweet!
Just found another research article that pointed out that graphene structures can be considered to be collections of benzene chains.
since it is easier to fabricate graphene sheets with induced defects, it would seem quite likely that we could use the armchair style graphene, with defects seeded just inside the edge, that would mimic these offset benzene chains with something that is a lot less toxic in bulk.
would be a great way to fabricate strips, but the paintable coating style will prob still have to be made with these benzenes.
Just found another research article that pointed out that graphene structures can be considered to be collections of benzene chains.
since it is easier to fabricate graphene sheets with induced defects, it would seem quite likely that we could use the armchair style graphene, with defects seeded just inside the edge, that would mimic these offset benzene chains with something that is a lot less toxic in bulk.
would be a great way to fabricate strips, but the paintable coating style will prob still have to be made with these benzenes.
Want to RUN !!
Think this would be a great base for the solar panels for our asteroid miners over at NEAmines@Y*hoo.
Seems like it will be a perfect heat sink on the inside , and a great base for the collector panels on the outside.
Want to use nanotowers silkscreened onto the conductive laminate, to collect all the IR and UV, not just the visible.
This gets rid of radiators AND solar panels sticking out!
Think this would be a great base for the solar panels for our asteroid miners over at NEAmines@Y*hoo.
Seems like it will be a perfect heat sink on the inside , and a great base for the collector panels on the outside.
Want to use nanotowers silkscreened onto the conductive laminate, to collect all the IR and UV, not just the visible.
This gets rid of radiators AND solar panels sticking out!
so this actually may be an effect of the benzene structure, rather than a thermodynamic ?
edit: http://www.physorg.com/news/2011-04-sel ... onics.html
edit: http://www.physorg.com/news/2011-04-sel ... onics.html
Re: The REAL thermo-electric effect. With variations ?
That's great. And you'll be following up on your main reason for posting on the forum [which is an interest in fusion energy, and Polywell - right?] sometime soon.morganism wrote:Hey folks !
Have been around here following Mach engines, ENR microwave engines, Rossi stuff, etc,etc... and lots of follow-ups on Next Big Future topics.
Finally decided to register, because i would like to float some ideas we need for our NEA mining group over on Y*hoo groups.
It is coming together quite nicely tho....
They just found that backing a solar panel with cesium traps the IR, and works best at 200c, when visible is flailing.
Can prob do it with a couple layers of Mylar, layer the top conductor down to the bottom conductor with graphene armchair ribbons. and painting cesium on top with a roller, then sputtering on nanopillars.
Getting the graphene to attach to both of the mylar layers may be tricky, but here is how you can make 'em. Would still be easier with the benzene, they say it is self organizing .
http://www.sciencemag.org/content/331/6021/1146.short
And you have yourself a full spectrum wavelength converter, and a heat sink/radiator in a single laminate package. And the power source as an added benefit- when it started out as the target !
Make the outside of the ship or satellite coated with that, and you have solved a lot of the radiation hardening problem, and gotten rid of pesky outriggers that mess with C of G and solar steering, and acceleration torque issues.
It may be that the cesium is acting like a quantum well by self forming into a Efimov state well, at high temps.
If they are working like traps with all the folding available, but that is just a wild speculation.
a topological view of a different state of matter.
http://www.technologyreview.com/blog/arxiv/26144/
http://www.technologyreview.com/biomedicine/20239/
http://www.technologyreview.com/energy/25971/?a=f
They just found that backing a solar panel with cesium traps the IR, and works best at 200c, when visible is flailing.
Can prob do it with a couple layers of Mylar, layer the top conductor down to the bottom conductor with graphene armchair ribbons. and painting cesium on top with a roller, then sputtering on nanopillars.
Getting the graphene to attach to both of the mylar layers may be tricky, but here is how you can make 'em. Would still be easier with the benzene, they say it is self organizing .
http://www.sciencemag.org/content/331/6021/1146.short
And you have yourself a full spectrum wavelength converter, and a heat sink/radiator in a single laminate package. And the power source as an added benefit- when it started out as the target !
Make the outside of the ship or satellite coated with that, and you have solved a lot of the radiation hardening problem, and gotten rid of pesky outriggers that mess with C of G and solar steering, and acceleration torque issues.
It may be that the cesium is acting like a quantum well by self forming into a Efimov state well, at high temps.
If they are working like traps with all the folding available, but that is just a wild speculation.
a topological view of a different state of matter.
http://www.technologyreview.com/blog/arxiv/26144/
http://www.technologyreview.com/biomedicine/20239/
http://www.technologyreview.com/energy/25971/?a=f
Here is the local PBS affiliate interview with the guys down at U of Az.
http://www.azpbs.org/technology/play.php?vidId=2589
http://www.azpbs.org/technology/play.php?vidId=2589
From the interview they seem to say that their material is cheaper, and "much more efficient" than conventional thermocouples. The much more efficient is the key phrase. Conventional thermocouples are perhaps 3-5% efficient. If this could increase this to 40 or 50% it would be tremendous. It would not eliminate radiators, etc, but it could greatly reduce them. The cost per unit of electricity produced may be just as important.
Dan Tibbets
Dan Tibbets
To error is human... and I'm very human.