Heated tank to mitigate surface tension?

[Slatye]

A peristaltic pump seems like a good option for this. A small, constant volume delivered on each revolution is exactly what we need, and it should be largely immune to corrosion from salt water. And, of course, they're only a couple of dollars on eBay.

It'd also open up some really interesting possibilities - you could build a perfectly horizontal surface just by turning off the pump for a while and continually drawing slightly larger shapes with the laser. Obviously with the dripper you can't do this properly; it may take thousands of laser passes to build a large flat surface and in the time it takes to do those the dripper will have raised the surface substantially.


Edit: ooh, you can get stepper-motor peristaltic pumps on eBay! They're not cheap ($50 AU or thereabouts), but for extremely small and accurate movements they'd be perfect. With a DC one, I'm not sure how you'd tell where it's up to - maybe measuring current or with a magnetic sensor.