One would take an array of transparent acrylic tubes and place them next to each other. Like in old church organs or pan-flute. Attach air hoses to the bottom part of the tubes and feed them to magnetic valves. After the valves there is an air compressor. Finally, fill the tubes with some liquid, colored or transparent.

Idea would be to push air bubbles to inside the tubes that would then slowly raise to the top. When the first bubbles are going up the valves release a new burst of bubbles in for the tubes that need them etc. By doing this, one could write messages or draw images that would then slowly disappear when the bubbles reach the liquid surface.

This would be great for trade shows or to display status information about your computer on case side window etc. Can be made small or really large to cover large surface area. Also with some colored spotlights shining from the top towards the acrylic tubes the bubbles would be even more visible.
-- japala, Oct 08 2003

Tubed colored liquid display http://www.halfbake..._20liquid_20display
[mr2560, Oct 17 2004]

It's been done (PDF) http://www-2.cs.cmu...les_paper_draft.pdf
(originally linked by egnor on "Liquid Letters") [half, Oct 17 2004]

The liquid would have to be fairly viscous to allow persistance of the message.
-- oneoffdave, Oct 08 2003


A cool replacement for neon.

Would help me teach terminal settling velocities to the students as well.
-- suctionpad, Oct 09 2003


I think this is what you are describing (link).
-- half, Oct 09 2003



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