Silica Aerogel .1-1mm granules as LED diffuser material

127.0.0.1

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Hi,

I made two diffusers:

a) a room light. stick an LED flashlight under it and it lights up the entire room.
I used a TechLight LumenMaster as a mule for this, and 1 pint of Aerogel grains in
a clear plastic bottle container.

b) diffuser inside the LED light bezel for flood.
used a Mag 2xAA with NiteIze mod, and stuffed grains directly on the emitter
and filled it up to the glass.


Both diffusers barely decreased luminosity, if at all....and had zero artifacts. These work amazingly well.
I used silica aerogel 2nm sphere in 100nm pore clusters, ground up into .1mm-1mm size random grains.

The aerogel is optically pure on the nano-scale, and with all the spheres, pores, and grains...the light really spreads
everywhere perfectly and with absolutely zero artifacts.


I would post pictures but the forum won't allow me to.

Anyone else used Aerogel ? I am not kidding when I say...this might be the -absolute best way- to diffuse LED emitters.
 

GeoBruin

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I have a liter of granular aerogel sitting around, but I'm having a hard time picturing how you created a diffuser from it. Just keep posting and eventually you'll be able to post pictures.
 

127.0.0.1

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easy.

static-free environment (or have a vac handy)

open bezel to expose reflector and emitter...dump in a mound of grains...just a little bit heaping...squash bezel back together...presto !

in production I'd envision a drop-in reflector replacement which is pre-packed. an aerogel diffuser will not be
small and thin and bendy, it would either need to be a pre-packed reflector assembly or a glass sandwich 5mm thick.

I did it on a whim, and was pretty surprised ay how much light is not lost, yet perfectly diffused
 

127.0.0.1

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I have pics, but am not allow to post them yet. I did not measure light loss with proper equipment.
Even though I have 1cm of aerogel in the bezel I can still peek through it and tell there is a yellow puddle emitter in there.
Aerogel does odd stuff with light that passes though it. Far different that what a bunch of broken glass chunks would
do to light, [which is what aerogel grains are essentially...a bunch of broken glass], but with billions of nanoscale spheres and pores.

if someone did choose to use it as diffuser material, it is bulky and a bit messy, so I am not saying that -the installation of it-
is ideal, but the diffusion it creates I think is ideal due to how little it impedes lux.
 

Helmut.G

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Nobody is allowed to attach pics on CPF. You need to upload them to an image hoster and put the pic's url between [/lMG] tags.
Note the maximum allowed size is 800x600 pixels.
 

DM51

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Nobody is allowed to attach pics on CPF. You need to upload them to an image hoster and put the pic's url between [/lMG] tags.
Note the maximum allowed size is 800x600 pixels.[/QUOTE]
Correct!

Anyone can post pics - use Photobucket, flickr or one of the other hosting sites. See [URL="http://www.candlepowerforums.com/vb/showthread.php?327532-Posting-photos"]this thread[/URL] on how to do it.
 

127.0.0.1

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nope, can't be linking to images. can't be creating albums on other sites. Oh well, no pics then. sorry for the bother.
 

Foxx510

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I was thinking about using glass microspheres in parafin in a lamp project as a diffuser, but this stuff sounds way better. Now to find if I can buy it!
 

AnAppleSnail

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United Nuclear will sell a jug of this stuff

http://unitednuclear.com/index.php?...esult&search_in_description=1&keyword=aerogel


I will go check Imgur and see if I can post pics.

In the meantime, guess what I have been up to ? Talking to Fred, and he is gonna design me a light.

I might be a noob but I think I am a flashaholic

Everyone is welcome here. If you have a digital camera, you could try this semi-useful brightness test:

Mount the camera on a tripod. Take a picture of a room with the flashlight shining on the ceiling. Note the exposure time.

Pack the aerogel dust in. Do the same procedure.

ASSuming the auto exposure has some sense, then:
-The ratio of exposure times tells us the relative brightness

You can look at the .exif data (right-click, info, 'more info' or something) to see the exposure time of the digital file.
 

bob4apple

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Hmmmm....I've seen aerogel demonstrated as the world's best insulator, with a blowtorch touching
a thin slice of areogel, and a hand touching the other side, with no harm done.

So I'm thinking it may prevent heat from escaping upwards, away from the LED, if you pack that
aerogel dust against it. How important that particular thermal pathway is in any particular flashlight,
I surely wouldn't know.
 

127.0.0.1

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^right

I don't plan on using my light for long burntimes, but you have a point

how much heat needs to dissipate off the emitter that doesn't go through the heatsink
would be a consideration for a diffuser that butts up against the emitter. I don't think
any serious diffuser would touch the emitter, but for the common hobo doing this
in the backroom...good question
 

kaichu dento

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how much heat needs to dissipate off the emitter that doesn't go through the heatsink
would be a consideration for a diffuser that butts up against the emitter. I don't think
any serious diffuser would touch the emitter, but for the common hobo doing this
in the backroom...good question
I'm sure that it's okay to do these as you are with no concern for heat entrapment, as that function is being carried out through the base of the emitter and whatever heat does escape atmospherically would be inconsequential compared to the physical coupling at the base.
 

bob4apple

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I'm sure that it's okay to do these as you are with no concern for heat entrapment, as that function is being carried out through the base of the emitter and whatever heat does escape atmospherically would be inconsequential compared to the physical coupling at the base.

Maybe, but the only way to be absolutely sure is to test. In effect, by blocking heat escape from the front, the emitter base will have to deal with
more heat than before, and many flashlights are already operating beyond safe heat limits.

Anyway, I'm glad for the experiments with high tech diffusion material. I'm tempted to try it out with a cheap light that will
volunteer to donate its LED to science in case anything goes wrong.
 

kaichu dento

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Maybe, but the only way to be absolutely sure is to test. In effect, by blocking heat escape from the front, the emitter base will have to deal with
more heat than before, and many flashlights are already operating beyond safe heat limits.

Anyway, I'm glad for the experiments with high tech diffusion material. I'm tempted to try it out with a cheap light that will
volunteer to donate its LED to science in case anything goes wrong.
I highly doubt that there is any significant amount of heat being exuded through the air trapped inside the lens.
 

127.0.0.1

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OK

holy crap imgur is simple
----
picture inside the maglite head, you can just tell it is chunks of aerogel
wkCmi.jpg


picture of the hobo room lantern with techlite lumenmaster as a base, on low, lights up the whole kitchen
KQVnn.jpg


picture of the diffusion from the maglite against my basement wall, pretty even compared to non-diffused
LHidC.jpg


I do not have light measuring equipment, but I could not tell the light was reduced at all, except the hotspot was removed
 
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