– 20Minuten (German) by Fee Anabelle Riebeling | English translation by Quang Thai –
Many of us are still nostalgic about the classical light bulb, because they are no more available since 2012. Thank to nanotechnology they may get a comeback after all.
Classical light bulbs are extremely inefficient, because they emit 90 percent of their energy as heat and not as visible light. For that reason, 1st September 2012 was the day in Switzerland when the last bulbs were sold. Eversince, energy saving light bulbs (see note at the bottom), halogen lamps and LEDs illuminate the buildings in this part of the world – at the cost of all those who liked the warm light that the obsolete incandescent light bulbs emitted.
However, a solution is on the way: as reported in the science journal «Nature Nanotechnology», Ognjen Ilic and other researchers from the Massachusetts Institute of Technology (MIT) have found a way to increase the efficiency of the incandescent light bulbs.
First success, high ambition
Ilic and his colleagues coated the classical light bulb filament with a special nanostructure. This special filament lets visible light pass, but blocks infrared light. That way, 80 to 92 percent of the thermal radiation are reflected back to the filament and gets absorbed.
The clou: the energy does not dissipate, but rather contributes to the heating-up of the filament and thus, energy can be saved. According to the researchers, the prototype has a considerable luminance efficacy than ordinary light bulbs. Moreover, they want to further improve the technique and boost the luminance efficacy up to 40 percent.
Another advantage: the required materials are abundant, which keeps the manufacturing cost of these new kind of light bulbs relatively low.
Note: economical, but toxic
Energy saving light bulbs require much less energy, compared to the obsolete incandescent light bulbs. That’s why they seem to be environment-friendly. But these new lamps are problematic for the environment, because they contain mercury which is a health-hazard.
Link to original article:
Wissen | Die Glühbirne steht vor einem Comeback