We all hate it: clogged inkjet nozzles. They smudge and make your "photo quality" printer a dud.
Jae Wan Kwon, associate professor in the College of Engineering at the Uniersity of Missouri, decided to do something about it. He turned to the human eye for inspiration.
An eye stays moist because it is covered with a thin film of oil. Kwon decided to do the same thing for inkjet nozzles, except he used silicone oil.
He couldn't duplicate the eye exactly; the eye has eyelids that spread the film of oil over the layer of tears. An "eyelid" on a printer, such as a mechanical shutter, would add a level of complexity to the printer and would get trapped in place by the surface tension of the oil. Kwon used an electric field to move the droplet of oil instead.
This would be a big improvement on the current method, which is just to have ink droplets break through the dried gunk that forms on the nozzles if the printer isn't used a lot. When it prints, a burst of fresh ink breaks through. Over time this can waste a large amount of (expensive) ink. Kwon’s invention eliminates that waste.
And it isn't just inkjet printers. Rapid protoyping machines (3-D printers) run into similar problems. The liquid used in them can make it necessary to replace the whole nozzle when they get clogged — at a cost of thousands. If those nozzles can be rendered clog-free, it would save a lot of money there as well.
Image: Wikimedia Commons