Laser Draws Tiny Channels for Water express
A laser beam passes through glass and touches a thin diamond film. At the point of contact, the film turns into a narrow strip that lifts slightly. We place a second strip next to it, and between them remains an empty corridor. That's the channel: its width can be fifty times its height, like a sheet of paper lying on a table.
Water flows into the channel by itself, like into blotting paper. No pump needed — the liquid creeps along the slit thanks to attraction to the walls. The channel doesn't break down even when completely filled. Through the transparent glass, you can see water moving inside: light reflects differently from filled and empty sections.
This method is like drawing with a laser on glass. Two lines, and a channel is ready between them. No complicated assembly, no gluing. This paves the way to cheap and reliable devices where liquids flow through ultra-thin flat slits.
Water flows into such a channel by itself, without a pump, like into a dry sponge dipped in a puddle.