"The eye and an ink jet nozzle have a common problem: they must not be allowed to dry while, simultaneously, they must open," explains Jae Wan Kwon, associate professor in the College of Engineering at the University of Missouri. Kwon, with the help of MU engineering doctoral student Riberet Almieda, solved the problem of the clogging inkjet printer by imitating the human eye's own solution to dry exposure, a scientific approach known as biomimicry.
Inspired by the thin film of oil that the eyelid spreads over the layer of tears to keep them from evaporating, Kwon's clog-preventing nozzle cover uses a a droplet of silicone oil to cover the opening of the nozzle when not in use. This droplet is moved in and out of place by an electrical field, as tiny eyelid-mimicking shutters at the small scale of the printer nozzle would be stuck in place by surface tension, unable to move as desired.
If not in constant use, the printer nozzle typically clogs over with a crust of dried ink -- think of a clogged toothpaste tube or a blocked bottle of lotion; it's the same predicament. To break the blockage, the printer shoots a burst of fresh ink through the crust, clearing the way. This is a lot of wasted, expensive ink. Not to mention an environmental strain, what with all the additional cartridges these printers use up.
And as increasingly many uses are being discovered for 3D printing technology, a little lost ink ceases to be the concern, Kwon explained to MU News:
"Adapting the clog-free nozzle to these machines could save businesses and researchers thousands of dollars in wasted materials. For example, biological tissue printers, which may someday be capable of fabricating replacement organs, squirt out living cells to form biological structures. Those cells are so expensive that researchers often find it cheaper to replace the nozzles rather than waste the cells. Clog-free nozzles would eliminate the costly replacements."
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