|Inkjet printer can sit idle for weeks or even months before being called
into service. And when it is called upon, the long break between print
jobs means the print heads are usually clogged and an ink-wasting head
clean needs to be performed. Taking inspiration from the human eye,
researchers at the University of Missouri have developed a print nozzle
that prevents the ink inside from drying out when not in use.
To keep the surface of our eyeballs moist, our eyelids spread a film of
oil that prevents a thin layer of tears from evaporating. Recognizing
that the same principle could be used to keep ink from drying out in the
print nozzle opening, the researchers developed a system that uses a
droplet of oil to block air from getting to the ink in the nozzle and
drying it out.
Because mechanical shutters like eyelids would not work at the small
scale of the inkjet nozzle, as the droplet would stay in place thanks to
surface tension, the system uses an electric field to move the droplet
of oil in and out of place. The technology could be adapted for use in
other devices in which the material being sprayed through the nozzle is
even more valuable and expensive than ink - hard as that may be to
believe, such substances do exist, according to the researchers.