Geeko friendly's List: Nano

• an adhesive made of carbon nanotubes whose structure closely mimics that of gecko feet. It's 10 times more adhesive than the lizards' feet and, like the natural adhesive, easy to lift back up. And it works on a variety of surfaces, including glass and sandpaper.

• A new antireflective coating developed by researchers at Rensselaer could help to overcome two major hurdles blocking the progress and wider use of solar power. The nanoengineered coating, pictured here, boosts the amount of sunlight captured by solar panels and allows those panels to absorb the entire spectrum of sunlight from any angle, regardless of the sun’s position in the sky.
• An untreated silicon solar cell only absorbs 67.4 percent of sunlight shone upon it — meaning that nearly one-third of that sunlight is reflected away and thus unharvestable
• new nanoengineered reflective coating absorbed 96.21 percent of sunlight shone upon it — meaning that only 3.79 percent of the sunlight was reflected and unharvested.
• This huge gain in absorption was consistent across the entire spectrum of sunlight, from UV to visible light and infrared, and moves solar power a significant step forward toward economic viability.

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• This cell is extremely promising because it is made of low-cost materials and does not need elaborate apparatus to manufacture. In bulk it should be significantly less expensive than older solid-state cell designs. It can be engineered into flexible sheets and is mechanically robust, requiring no protection from minor events like hail or tree strikes. Although its conversion efficiency is less than the best thin-film cells, its price/performance ratio (kWh/M2/annum) should be high enough to allow them to compete with fossil fuel electrical generation (grid parity).
• By far the biggest problem with the conventional approach is cost; solar cells require a relatively thick layer of silicon in order to have reasonable photon capture rates, and silicon is an expensive commodity.
• There have been a number of different approaches to reduce this cost over the last decade, notably the thin-film approaches, but to date they have seen limited application due to a variety of practical problems. Another line of research has been to dramatically improve efficiency through the multi-junction approach, although these cells are very high cost and suitable only for large commercial deployments. In general terms the types of cells suitable for rooftop deployment have not changed significantly in efficiency, although costs have dropped somewhat due to increased supply.
• As a result of both of these features —low losses and lack of recombination— DSSc's work even in low-light conditions. DSSc's are therefore able to work under cloudy skies and non-direct sunlight, whereas traditional designs would suffer a "cutout" at some lower limit of illumination, when charge carrier mobility is low and recombination becomes a major issue. The cutoff is so low they are even being proposed for indoor use, collecting energy for small devices from the lights in the house.
• A practical advantage, one DSSc's share with most thin-film technologies, is that the cell's mechanical robustness indirectly leads to higher efficiencies in higher temperatures. In any semiconductor, increasing temperature will promote some electrons into the conduction band "mechanically". The fragility of traditional silicon cells requires them to be protected from the elements, typically by encasing them in a glass box similar to a greenhouse, with a metal backing for strength. Such systems suffer noticeable decreases in efficiency as the cells heat up internally. DSSc's are normally built with only a thin layer of conductive plastic on the front layer, allowing them to radiate away heat much easier, and therefore operate at lower internal temperatures.
• The major disadvantage to the DSSc design is the use of the liquid electrolyte, which has temperature stability problems. At low temperatures the electrolyte can freeze, ending power production and potentially leading to physical damage. Higher temperatures cause the liquid to expand, making sealing the panels a serious problem. Another major drawback is the electrolyte solution, which contains volatile organic solvents and must be carefully sealed. This, along with the fact that the solvents permeate plastics, has precluded large-scale outdoor application and integration into flexible structure.^[13]
• Another problem with the current cell design is limited electron mobility at lower energies. This makes the DCCs inefficient at collecting energy from the red end of the spectrum. There are a number of efforts to improve this, typically using thin wiring to provide a second low-resistance route for these electrons.

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• Dr. Danijel Rebolj
• V računalniku ustvarite popoln digitalni model zgradbe, z vsemi stopnicami, okni, napeljavami. Na izbrano zemljišče pripeljete poseben visokoločljivostni projektor in ga čvrsto pritrdite nekaj metrov nad tlemi. Vanj vnesete digitalni model želene zgradbe. Na načrtovani tloris nanesete potrebno količino bionanorobotov, umetno ustvarjenih mikroorganizmov, programiranih za proizvodnjo ogljikovih nanocevk. Prižgete projektor, ki začne oddajati različne valovne dolžine svetlobe in pošiljati ukaze »nanodelavcem«, ti pa na podlagi prejetih ukazov atome ogljika sestavljajo v različne strukture karbonskih nanocevk, plast za plastjo. Če gradijo stene, izdelujejo inertne strukture, če gradijo napeljavo, mora struktura ogljikovih atomov v nanocevkah omogočati elektroprevodnost, če so na vrsti okna, pa prozornost materiala. Celotno zgradbo zgradite iz enega materiala, ogljika, ki ga bionanoroboti pridobijo kar iz okoliškega zraka. V nekaj deset dneh imate novo hišo. Projektor ugasnete, kar je znak bionanorobotom, naj se ugasnejo oziroma umrejo tudi sami.
• Potem je tu še izdelava stekla, plastike, prevoza materiala ... vse to ni več potrebno.
• Po izračunih bi s takim načinom gradnje glede na gostoto ogljika v zraku lahko zgradili približno meter višine na deset dni. Površina zgradbe bi bila omejena zgolj s količino bionanorobotov in zmogljivostjo projektorja oziroma projektorjev.
• Najbrž pa bo težko z eno potezo rešiti vse probleme hkrati - izkoriščanje sončne energije, odstranjevanja ogljika in njegovo skladiščenje v zgradbah. Ampak že samo delna rešitev bi znala biti zelo uporabna.
• A ker je dr. Rebolj prepričan, da bi morala biti ta tehnologija javno dobro, je z objavo koncepta, poimenovanega n2mBuilding, pohitel, saj, kot pravi, že objavljene zamisli ni mogoče patentirati.

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