Build LED Glow Tubing

I love LED's and am always looking to use them in new ways. Especially for cool effects. I found a great way to couple a blue LED into 1/4 inch tubing. Then by filling the tubing with fluorescent liquid, a glow tube can be created. It took a little experimentation to get right and ended up being very simple. Here is what you will need:

1. Quarter inch clear Tygon tubing (Lowe's or Home depot carries it)
2. Ultra bright blue LEDs (5mm, clear lens, narrow beam i.e. 12-15 degrees)
3. A small plastic squirt bottle similar to a condiment dispensing bottle 
4. a Fluorescent Highlighter (Available at most office supply stores)

Step 1: Preparing the Florescent Dye

The first step is to prepare the dye. Take the back off of the fluorescent highlighter. You can ether pry the ink reservoir out. It is an absorbent cylinder soaked in the dye. My first try at this I pulled it out and used a lot of the dye. I put about a teaspoon into the plastic squeeze bottle. This was way to much. It causes the light to be used quickly and not travel far down the tubing.

What ended up working best and is easiest it to place the end of the highlighter over the mouth of the squeeze bottle and let the water absorb some of the die

Comments

[sinepo]

are these normal led or gree led?

[DJJules]

They are blue LED's. I also tried UV but the blue worked better

Jules

[solo7319]

Wow, seems like there's a lot of debate online in general about the best combination of light source and fluid for different colours and maximum illumination. I've noticed it seems to be common to finely sand the tubing in order to frost it and further diffuse the light so I'm going to give that a try as well.

For those considering different colour options with UV-sensitive liquids, this page has a decent list of substances with different colour results under UV:

http://chemistry.about.com/cs/howthingswork/f/blblacklight.htm

[DJJules]

Thanks for that link. I need to update this with some more info. I bought one of those commercial water safety dye markers that is pure florescene. Want to try mineral oil too. It would be good to find a suspension particle for the liquid that would alleviate the need to sand the inside of the tubing.

Jules

[ade souza]

cool much cheaper than el wire..

[DJJules]

Thank you!

[zorwick]

Great idea,congrat!
I need something smilar now for one m new projects. Question is how long that fluid is fluorescent? The chemical rods are just for short time, the EL wires for a few months maybe...What do you think about this?
Thanks

[DJJules]

THe fluid remains fluroescent a long time. THe problem I have seen is the tube dries up after a year or so. What I need to try (And it is on my to do list) is dissolving the fluoresene in mineral oil or the like.

Jules

[Luziviech]

...that already exists. I once bought a canister of that stuff on ebay. The vendor said, it's generally used by Airbus to find tiny cracks in airplane wings. I used it as paint, but it's volatile and nearly gone after a month or so.
You can also buy Fluorescein as a dry powder. And check out this instructable; might come in handy, if you want to make sumthin bright, i guess: http://www.instructables.com/id/Building-a-Lightsaber/

[Chaspudz]

Hey Jules,
Is there anyway i can get in contact with you?
Im looking at using this idea in a product im making and would be intrested in any new developments or better solutions to use in the tubes for my product
Thanks Elliott, [e-mail]

[OT4]

Great instructable! I love these. I was looking for something like that. I will make this so they flash to my music then wire a bunch of them around my room. Thanks again for this great ible.

[DJJules]

You are welcome!

[Attmos]

i love this idea. i used this concept in something i made, thanks for the inspiration. i posted it if you want to take a look.

have fun

[DJJules]

Thanks! I just got a couple ten watt Blue LED emitters that I am hoping to have time to get to for this one on steroids. Check it out here: http://www.dealextreme.com/p/10w-180lm-445-447nm-blue-light-led-emitter-9-11v-100875

Jules

[Oimi]

Is there a better way of securing the batteries so they can be added and removed easier? I would be looking to swing these about for light painting but would be worried the battery would fly out as well.

[DJJules]

If you solder wires to the LED, you can run them back to a battery in your pocket and only sing the tubing part. Also if you use a nine volt battery, you need to add a 200-300 ohm resistor in series.

Have fun!

Jules

[plmqaz1243]

Oops. I didn't read the next page yet.

[plmqaz1243]

Couldn't you use UV Leds?

[jconner3]

ok ill be hounest im lighting up my deadmau5 helmet and i cant figure out the resistor i need to wire 12 white leds too what even portable power sorce i need i need help i have a on off switch 12 white leds and the toobing

[DJJules]

If you are using a white led each one drops about 3.5 volts and you want about 20ma to each so you need a resistor that would be (your supply voltage -3.5) divided by .020 amps. In a nut shell 200-330 ohms for 10-12 volts and about 75-100 ohms for 5-6 volts.

Post a pic when you are finished!

Jules

[jconner3]

soo what battery should i use

[Jack Corsair]

so for the blue color you used what?

[ZeroXL91]

Come to think of it, couldn't you use use EL Wire to illuminate the water? It would be so much brighter!

[Xiero]

If your using UV led's, have you considered using tide detergent? I work on a tech crew and we have these 18" UV cannons that we shine at a wall which we painted with tide. the effects are pretty sweet. The only problems i forsee is coming up with a diluted solution that doesnt creat suds...

[douks]

who can send me The PDF Format of this Project please

[Huntman00]

How long it the tube in the last and second to last pic on step 5????????

[CaseBoy]

how long is the biggest one?

[DJJules]

about 18" but the glow isn't even across the tube, it falls off away from the LED

Jules

[CaseBoy]

so how long can the tube be without the glow dimming?

[scorpenzy]

How do you manage the color, by the LEDs or the hilighter itself? And how do you make a red tube? Last thing, how long can you make the tube while still looking neon?

[DJJules]

The tubes as I built them are using florescent dye that glows yellow/green with blue light exciting the dye. I did try a ultra bright red LED in cloudy water (add a pinch of Corn Starch to a cup of water) and it works. The light intensity falls off as you move away form the LED so it isnt as effective as a neon tube.

[phevtron]

made one which is ''dancing'' to the beats

[kumiko]

This sounds like a great idea in creating the leggings part of this costume:
http://vocaloid.wikia.com/wiki/Piko_Utatane

It might even be possible to attach tubes in a cross shape, but I can't be sure.

Have you tried blue highlighters with blue LEDs?

[ilpug]

could you use the button cell batteries taken from inside AA batteries to power this?

[G-Nugget]

I've been experimenting with these tubes for use around the edge of a clock I'm making with an acrylic face. I am using 3/16" internal diameter tubing and been successful with getting the LEDs a few millimeters into the tube and sealing with silicone.

I found a solution that is a very pale yellow without light but glows very well when lit. The problem that I'm having is that the dye appears to be disappearing. The tubes go from glowing green to eventually being all blue with no fluorescence over a period of usually a couple of days. I noticed that the pictures here show the tubes being mostly blue; is that just the camera? I tried exposing the tubes to UV from a strong black light for days, heating the tubes, and just letting them sit for a while, but the fluorescence only disappears when lit by the LEDs in the ends. I haven't been able to rig something up to expose the tubes to external LEDs. I'm out of ideas for what would cause the dye to decay. Am I doing something wrong or is this normal?

[DJJules]

Mine still are working. What type of Highlighter did you use? I had a challenge coming up with the correct amount of dye. I first squeezed the highlighter liquid into my squirt bottle but it was too strong at first. I am going to go back and try mixing some rubbing alcohol in there to prevent any mildew/mold. fluorescent compounds do not lose their ability to floresce after time.

[G-Nugget]

I'm using a highlighter I had laying around at home. it's just a basic yellow fluorescent highlighter. I have been adjusting the solution and when I first noticed that the tubes were losing the color I added more and it stayed for longer. I'm going to add some more and make another and see if that helps more.

I know it sounds crazy, but the the fluorescence disappears from the ends first, then moves towards the middle. I can't say anything for sure about the mix chemically, but it definitely doesn't fluoresce and doesn't become more concentrated in the areas that still do. The ends are very well sealed and nothing has leaked out. I'm going to take some pictures tonight so what is happening is easier to understand.

[G-Nugget]

pictures: http://s264.photobucket.com/albums/ii173/GNugget0/projects/

Both tubes were made identically and the only difference is that I have had tube 2 lit on the LEDs for about four days and tube 1 for about one day.

[DJJules]

OK, I did a little research and interestingly, the absorption for Fluorescein is close to a Blue LED which is very cool. It is added to bubble levels which make the liquid brighter and show up green. But, it is dissolved in Alcohol when they do that. So, gimmie a couple days and I will try to make a tube that is 50-50 isopropyl alcohol and water.

Jules

[G-Nugget]

I originally tried adding some isopropyl alcohol to the mix, but for a reason that I don't remember, I decided that just water worked better.