Jeffbeerman2

Pulled from yahoo news. The whole friggin bike could be a light with this invention.

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Accidental Invention Points to End of Light Bulbs Bjorn Carey
LiveScience Staff Writer
LiveScience.com
Fri Oct 21, 5:00 PM ET



The main light source of the future will almost surely not be a bulb. It might be a table, a wall, or even a fork.


An accidental discovery announced this week has taken LED lighting to a new level, suggesting it could soon offer a cheaper, longer-lasting alternative to the traditional light bulb. The miniature breakthrough adds to a growing trend that is likely to eventually make Thomas Edison's bright invention obsolete.


LEDs are already used in traffic lights, flashlights, and architectural lighting. They are flexible and operate less expensively than traditional lighting.


Happy accident


Michael Bowers, a graduate student at Vanderbilt University, was just trying to make really small quantum dots, which are crystals generally only a few nanometers big. That's less than 1/1000th the width of a human hair.


Quantum dots contain anywhere from 100 to 1,000 electrons. They're easily excited bundles of energy, and the smaller they are, the more excited they get. Each dot in Bower's particular batch was exceptionally small, containing only 33 or 34 pairs of atoms.


When you shine a light on quantum dots or apply electricity to them, they react by producing their own light, normally a bright, vibrant color. But when Bowers shined a laser on his batch of dots, something unexpected happened.


"I was surprised when a white glow covered the table," Bowers said. "The quantum dots were supposed to emit blue light, but instead they were giving off a beautiful white glow."


Then Bowers and another student got the idea to stir the dots into polyurethane and coat a blue LED light bulb with the mix. The lumpy bulb wasn't pretty, but it produced white light similar to a regular light bulb.

White light from Bowers' lumpy new bulb. Credit: Vanderbilt University

The new device gives off a warm, yellowish-white light that shines twice as bright and lasts 50 times longer than the standard 60 watt light bulb.


This work is published online in the Oct. 18 edition of the Journal of the American Chemical Society.


Better than bulbs


Until the last decade, LEDs could only produce green, red, and yellow light, which limited their use. Then came blue LEDs, which have since been altered to emit white light with a light-blue hue.


LEDs produce twice as much light as a regular 60 watt bulb and burn for over 50,000 hours. The Department of Energy estimates LED lighting could reduce U.S. energy consumption for lighting by 29 percent by 2025. LEDs don't emit heat, so they're also more energy efficient. And they're much harder to break.


Other scientists have said they expect LEDs to eventually replace standard incandescent bulbs as well as fluorescent and sodium vapor lights.


If the new process can be developed into commercial production, light won't come just from newfangled bulbs. Quantum dot mixtures could be painted on just about anything and electrically excited to produce a rainbow of colors, including white.


One big question remains: When a brilliant idea pops into your mind in the future, what will appear over your head?

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slvoid

So basically he just found a way to disperse the light better from an LED?
Cause all they seem to be talking about are the LED's...

Look at this thing...

You gimme a 5 watt luxeon module and I stick it inside a lump of nylon and you'll get the same effect. You don't get something for nothing, whatever goes in comes out (usually a little less). All this is is a better way to disperse the light. I have a 1 watt luxeon that when overdriven 50% produces enough light to completely light up a 12x12 room. I can't imagine what a 5 or eventually 10-20 watt luxeon module would do.

jakemoffatt

slvoid i think that the "breakthrough" is not just a better way to disperse the light, but a means of producing actual "white light" with an led. the problem up to this point has been that a weird blue hazy light is the closest you can get to white with an led.
also, the light dispersion aspect of this "breakthrough" is a really big thing. if you want to buy an led light bulb to replace your current incandescent lightbulb you have to buy one with between 18 and 36 or more individual leds to get the same lighting from say a 60watt bulb. they have to also be arranged in a special pattern to get the same lighting equally around the room (dispersion). that you can get the same kind of lighting from one led (twice the brightness of a standard bulb, actually, isn't it?) is pretty impressive.

as always though we'll just have to wait and see if this pans out and ends up being all its propped up to be.

jyossarian

so how do i make my own quantum dots?

jakemoffatt

I couldn't quite be troubled to read this article but I think it almost answers your question:

https://www.aip.org/tip/INPHFA/vol-9/iss-1/p14.html

Cromulent

Sure, but then we get into a whole steel vs quantum dot argument, and no one needs that.

Cool article.

atbman

How much power does the laser you shine on the quantum dots, to make them glow, require?

JumboRider

I can see it now, cycle lycra made entirely from quantum dots. A car pulls in behind you and the driver is immediatly blinded as the headlites excite the wee dots. Blinded by butt cheeks so to speak.

Paul L.

Bluish (maybe white) Moon, you saw me riding alone....