When I was a kid I once saw at a musem an old 386 hooked up to 8 air pumps in a line at the bottom of a large column of water (or some more viscous liquid). The result was pretty cool, even in 8-bit: the bubbles created move up and you keep "printing" lines of bubbles with the pumps.
I've always wanted to recreate that with higher resolution and in 3D (think square column of water). But what I've never been able to find is the micropumps necessary to achieve this. Has anyone come across something like this? Or perhaps some small electric valve? I'm sure people use it in industry, I just don't know where they are.
I'd also welcome any thoughts on the project itself, like addressing lots of devices with only a few pins on the arduino.
I think Flexinol has a fairly slow response time (or reset time - I forget) - so I think it would be hard to get discreet, closely spaced bubble events.
A solenoid valve connected to some low pressure air source?
I checked electronic goldmine, which seems like a cool place, though they were out of valves right now. Any other part sites you guys recommend that might go beyond the usual electronics and have something like solenoid valves? And thanks for all the messages, I really do appreciate it!
One thing you should do is look for brick-and-mortar surplus dealers in your area: I got most of the weird parts in my shed back when I lived in Silicon Valley, and regularly cruised places that bought and dismantled equipment that was obsolete.
Parts bought from such dealers are nearly always cheaper than getting them by mail order, because there's no cost for photographing and cataloging them. Plus you can often get dirt-cheap prices if you by things "as-is": the occasional dead part is more than made up for by all the money you save. And you can often find items for which they only have 1, or 5, so it's not worth putting on the web.
A few of my favorite surplus places that deal in (some) non-electronic parts are Alltronics, American Science and Surplus, and BG Micro. Weird Stuff seems to have drifted more toward computer parts since I left Silicon Valley, but still has some "industrial" surplus.
The AS&S site is worth browsing for the entertainment value, even if you never buy anything: the catalog descriptions are a real hoot.
Also, just doing a google search for the parts you're looking for will sometimes turn up specialty dealers that you'd otherwise never hear of.
Im bothered by the fact that they are "normally open" meaning id have to power them constantly until i want a bubble released.
Yeah, that's not exactly "optimal" for your purpose. But they're cheap, and they only draw about 30mA apiece, so they're probably okay for experimenting.
