After he saw a ‘falling water display,’ [Matt] figured he could turn that idea on its head. He built a display that uses bubbles for pixels. Even though the build isn’t complete, we love the results so far.
[Matt] began his build constructing a tall, thin water tank out of acrylic. Eight solenoids were mounted in the base of the tank, attached to an aquarium air supply, plastic tubing, and one way valves. The first run of the bubble display didn’t go too well, but after adding dividers between each column the display started working.
With the dividers, [Matt] no longer had to worry about bubbles colliding or moving any direction but up. The bubbles weren’t moving consistently, so he replaced the water with mineral oil. Oil made a huge improvement, but the bubbles still float up at different speeds. [Matt] ascribes this to the unregulated air supply, but we’re thinking this problem could be mitigated with glycerine like the previous bubble display we saw.
It may still have some problems, but we love the result. Check out the video of bubbles in mineral oil after the break.
[youtube=http://www.youtube.com/watch?v=BMVmfARqBAA&w=470]
They have one of these installed at the science museum of Minnesota. A huge one, that covers a whole wall. They use clear tubes instead of channels between sheets like this, and the bubbles are kept rising at a consistent pace by making them match the diameter of the tube.
Also, the valves are set up in such a way that the bubble has time to stabilise. The tubes start out horizontal to the valve, then curve until they go straight up the wall. The curve seems to help shape the bubble so that it occupies the whole diameter of the tube, and rises at a consistent rate.
I have never seen pictures or video of this installation online, so next time I am there I will have to get some and share.
Very, very cool. A ‘professional’ version of this concept can be found in many science museums around the world – as PipeDream
Bruce uses semi-flexible tubes, and has sophisticated software doing the air injection timing to get all of the ‘pixels’ to line up just right at the moment that the last row is output.
It takes him about 2 days to ‘tune’ a 96-tube array because it involves multiple timing parameter changes and physical tweaking to each tube while running a variety of test patterns.
Very nice job Matt-
*Brian
Thank you for pointing that display out. They took a much much more controlled approach that I am. I have been hoping to leave it a bit more organic, but I am not sure if that is realistic now
BeagleBone + PSX guitar hero guitar = bubble hero
there is a pressure vacuum behind each bubble that “sucks” the bubble up behind it. I assume he’s scanning each row of pixels at once, but only one bubble is firing in just this example. He needs to increase the delay between each firing so that the pressure gradient in the tube has more time to settle.
It’s looped.
I take that back, it’s not looped. If you look at the left hand side, it gave me the impression that it was. After going back and seeing the right hand side, I realize it is not looped.
I’m guessing he’d need regulated pressure, and a good distribution system. I think, this is what I’ve seen working with water anyway, is if you simply put air/water into the end of a tube, with lots of take off’s along the way, the one at the end will ALWAYS have a problem(progressivly weaker as you love down the tube). The best way seems to be more like a “Y” set up, but with multiple take off’.
Possibly, each tube should have it’s only “tiny air tank”, to act sort of like a capacitor in a power supply.
Very cool project. I’d like to see this with some lights and graphics actually drawn in the tubes, or with music. That could be really coo..
good work!
A guy I used to work with built one of these, and used water, and that was about 1999 if I remember. Hit the link and scroll down to “Bubble Panel”. http://www.aquamationinc.com
Maybe if the oil had a constant upward flow, where the air didn’t have to boil its way up.
Temperature sensor on each tube and feedback to the system vith a little heater.
Inconsistent ascent speed problem should then go away.
I was thinking maybe the air pressure is still an issue and an air tank so that there is alot more volume might help, bit it would only be a band aid a proper fix is an air manifold and equal langth tubes to each solinoid, higher pressure line and very short pulse times.
I love this. What the expensive unit is missing is color.. I wonder if there’s a way to inject a dot of color into the the bubbles as they come out.
This is awesome.
Two words: Plenum Chamber
http://en.wikipedia.org/wiki/Plenum_chamber
Rather than a rat’s nest of tubes, a very large diameter tube/chamber with short takeoffs just ahead of each solenoid will work best and will keep the pressure relatively stable.