inkjet nozzle plates for gas flow?

[Rich Feldman]

Some of us love to explore solutions that avoid uncommon or expensive technologies.
Along those lines, I looked at the size of nozzle openings in an inkjet printer cartridge.

This example is from a relatively primitive HP51629A black cartridge. Each of the parallel rows has 27 holes with a pitch that appears to be 150 per inch, so diameter of about 2 mils (50 microns). At each end are three holes about half that size, perhaps for automatic optical alignment.

A simple orifice of even 1 mil is pretty large as a deuterium flow restrictor, but the path behind it (leading to ink reservoir) is surely not short and straight. Maybe newer, finer pitch consumer inkjet technology uses smaller nozzles. Might be fun to isolate one or two nozzles and measure their gas flow.

I do not propose that the built-in ink propulsion methods can be used to electronically turn nozzles on and off, or substantially vary their flows.

[edit] Just found this article about using regular inkjets to dispense biological cells. The writer points to a 1200 DPI printhead in which the nozzles are 23 microns in diameter. Deeper inspection reveals a micro-fabricated filter plate with holes about 3 microns in diameter. http://www.instructables.com/id/DIY-Bio ... igh-resol/
In recent years, printer advertising sometimes speaks of picoliters. A 3 pl drop is 18 microns in diameter. 1 pl sphere diameter is 12.4 um.

My last actual experiments in DIY flow control were in 2013: viewtopic.php?f=6&t=8725&p=60017 And yes, I do know how to get mass flow controllers.

[Richard Hull]

Interesting idea for a flow restrictor hack. I would think a single nozzle would be all you would need plus a small 1/16" bore, 4 foot capillary line from a needle valve. Somone will probably move on this suggestion as it seems a good one.

Richard Hull