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Scientist hope to put LEDs to work in brilliant new ways

LEDs, light emitting diodes, are a very old invention, with the first visible-light diode being invented in 1962.  They consist of a junction of semiconducting material, such as a silicon or gallium compound.  However, scientists today are looking to teach this old dog some new tricks, and putting LEDs to work in a plethora of creative uses.

The magic is in the material.  While LEDs have been around for a long time, new and exotic materials are being used and older materials are being tweaked and reformulated to provide, a wider range of colors, brighter light, and higher efficiency.

The result is that LEDs may soon be permeating our lives in new ways.  LEDs are already invading the automobile headlight industry and are in high demand due to their superior life and brightness. 

Now one place scientists are looking to plant the LED is in the home.  Tungsten lightbulbs have a very low 5% efficiency, compared to modern LEDs, which have around a healthy 40% efficiency.  The result is power savings, increased brightness, and superior life.  Obstacles standing in the way of this development are the still higher cost of LEDs and the fact that LEDs' white light has much more blue than sunlight or natural bulbs.  However, these obstacles are fading as costs slowly drop and scientists develop better material blends to provide more yellow to the LED's emissions, making for a warm light that would be welcome in many a household.

Scientists are also looking to put tiny LEDs to a new use in the lab and eventually in commercial internet connections -- quantum cryptography.  Tiny streams of photons in the system would pass from the LED to the a detector.  Any interception of the beam (ie. snooping) would result in the signal being altered, as per the observer effect.  Such a system, when properly implemented would be in theory immune to any sort of malicious interception between the sender and the receiver.

Yet another use for the little lights has been proposed by scientists -- this one with promise of bringing new high-tech hope to impoverished regions.  One of the world's largest problems is the lack of clean drinking water in third-world nations.  Chemicals can be used to treat drinking water, but they are often expensive, toxic, and require a large amount of infrastructure.  A frequently used alternative is high-energy UV light known as "deep UV", emitted from special UV bulbs.  Passing a beam of this light through water kills most bacteria and destroys most viruses cleanly and simply.  The issue with this system is bulbs constantly need to be replaced and are two bulky for small scale use.

Scientists feel the answer is deep UV LEDs.  While they are still working on perfecting the materials, researchers,  such as Dr Rachel Oliver, an LED researcher from the University of Cambridge, think it is just a matter of time before the optimal combination of materials is found. 

"Deep-UV can't be made from the combination of materials we're used to, although I certainly think it's possible," Dr. Oliver stated.

Dr. Oliver is among many researchers striving to put LEDs to use in new and creative ways.  She sees LEDs being commercially implemented in the aforementioned uses within 10 to 20 years.

For now these prospects still remaining cost prohibitive and are dependent on material breakthroughs, but the future sure looks bright for these little devices.  And companies are looking to put LEDs today to a different and even more outlandish use -- clothing -- every airport security officer's worst nightmare

Whatever their form, LEDs are transforming the way we light and see our world.


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By Rovemelt on 12/17/2007 2:19:36 PM , Rating: 2
I've been looking for LED replacement bulbs and I can find 'warm' color LED's that come in around 3500K, but they seem to suffer a bit in efficiency compared to the higher color temp LED's (~6000K), which looks blueish.

With regards to the efficiency quote from Mick, this is from the wikipedia entry on CFL's;

http://en.wikipedia.org/wiki/Compact_fluorescent_l...

quote:
While CFLs are an important development in energy conservation for most lighting, LED lighting has already filled a few specialist niches such as traffic lights and may have the potential to compete with CFLs in the near future. LED lamps have current efficiencies of 30% with higher levels attainable (recently up to 85 lm/w LED`s are available) , and a lifetime of around 50,000 hours, but currently are struggling to deliver the required intensity of light output for domestic uses while maintaining a reasonable working lifespan, at a reasonable cost.


I don't know how efficiency is being calculated, but they also put CFL's at 8%. Might have to do with what Masher pointed out regarding what light we can see vs. total light output being in the calculation.

There are portable UV water purifiers for sale out there. I have no personal experience with them, so I can't comment on their quality or effectiveness or the particular one I link to below. Even some that charge by a small solar panel:

http://www.hydro-photon.com/steripen_products.html




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