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Solid State Lighting

nh-leds.jpgLEDs -- light emitting diodes -- have the potential to be profoundly worldchanging. From the "Light Up The World Foundation" to boosting LED efficiency to match or even beat fluorescents, the cool light from LEDs will be a big part of the bright green future. But researchers at Rensselaer Polytechnic Institute have starting looking at some of the other applications of these solid-state lights (i.e., lighting that doesn't require filaments or funky gases, but instead is a solid electronic component) -- and what they found is pretty impressive.

In an article published May 27, 2005 in the journal Science, the authors describe research currently under way to transform lighting into “smart” lighting, with benefits expected in such diverse fields as medicine, transportation, communications, imaging, and agriculture. The ability to control basic light properties — including spectral power distribution, polarization, and color temperature — will allow “smart” light sources to adjust to specific environments and requirements and to undertake entirely new functions that are not possible with incandescent or fluorescent lighting. [...]

  • Recent research shows that ganglion cells in the human eye, which are believed to be involved in the human circadian or wake-sleep rhythm, are most receptive to the light in the blue spectral range that is experienced midday under clear skies. According to a basic physics definition, this light has a high color temperature, while evening light has a far lower color temperature. Lighting that offers the ability to adjust color temperature could benefit human health, mood, and productivity.
  • The ability to rapidly modulate LED-based light sources gives these lights the potential to sense and broadcast information by blinking far too rapidly for the human eye to perceive. Auto brake lights, for example, could communicate an emergency braking maneuver to a following car.
  • The ability to control the spectral composition, polarization, and color temperature of light used in microscopy could greatly improve the clarity of images, enabling real-time identification, counting, and sorting of biological cells for research and medical applications.
  • Controlling the spectral composition of grow lights would offer an energy-efficient method to grow fruits and vegetables out of season or in climates where they don’t usually flourish.

LEDs are cooler and more efficient than incandescent bulbs (the theoretical efficiency of LEDs is such that a 3 watt LED could produce as much light as a 60 watt bulb -- we're not quite there yet, unfortunately), and because they're electronic components, can be subject to far greater control and precision of use than previous lighting technologies. But getting to the point where we can start thinking of LEDs as reasonable replacements for traditional light bulbs was just the first step. As the RPI research suggests, the capabilities of "smart lighting" LEDs are far greater than just putting out light to read by, and we're just starting to explore what that might mean.

Comments (3)


Your email is broken. Send me a mail address that works. :) And please feel free to delete this.

Hi. This is the qmail-send program at mercury.polycot.com.
I'm afraid I wasn't able to deliver your message to the following addresses.
This is a permanent error; I've given up. Sorry it didn't work out.

Sorry, no mailbox here by that name. vpopmail (#5.1.1)

Jamais Cascio:

Actually, Thomas (and anyone else who reads this), suggestions can be sent via the suggestion form linked in the right-hand column, below the QuickChanges. Here's a direct link:

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What impact do the factories which produce these LED's have on the environment? Is it worth the savings? Has anybody thought to ask?


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