Of course you can hand pump juice. But you cannot, no matter how good you are, hand pump juice, with the same consistency as an automated, accurate dispenser.
Think about it.
If the human hand and brain, could deliver ink to the page, with the speed, reliability, and accuracy that an inkjet printer does, then people wouldnt be useing inkjet printers. We'd all be hand painting every image and document.
Do I think ive found the magic answer to ejuice delivery ? No.
Is it research candidate worthy of a simple bench test ? I think so.
That said, there are probably commercial sized piezo fluid delivery pumps out there somewhere, that use the same basic principles as an inkjet printer, but are slightly larger, and designed to dispense a more or less viscous fluid than those specifically designed for printers.
cmonkey