McKinley and Cohen are developing techniques for texturing surfaces with nanofabricated structures that form a forest of microscopic structures that look like tiny round platforms held up from below by thin pedestals. The structures are only about 200 nanometers in size; this is smaller than the wavelength of light, making them potentially transparent, McKinley says.
Theoretically, the tiny nail-shaped structures could be spaced at just far enough apart to prevent the liquid and oil droplets resting on top from combining with other droplets and spreading out. This coalescence and spreading out into a thin oily film is what causes surface smudging and smearing.
Today, McKinley says, he and Cohen in conjunction with another MIT professor, George Barbastathis, have successfully developed a highly transparent surface texture and chemical treatment that repels water, but doesnt yet effectively repel finger oil. Nailing that oil-resistant quality, however, is probably just a matter of time.
Daily wear and tear
Perhaps the most serious roadblock McKinley and Cohen are working through is the same one the researchers at the Max Planck Institute struggle with: Their surface treatment still is not durable enough to withstand a reasonable amount of the wear and tear that comes with the day-to-day life of a touchscreen device.
The real concern is the mechanical robustness, the reliability of the treatment, McKinley says. The oleophobic coating has to be tough enough to resist being scratched or rubbed off after coming into contact with objects like keys.
McKinley compares the challenge to the one faced by the developers of the Teflon surfaces used in nonstick frying pans. When they first came out with frying pans treated with Teflon to make them nonstick, they had same kind of reliability problems, but they still went to market, and, McKinley adds, the Teflon coatings got more and more durable after their introduction. McKinley believes the same thing will likely happen with smudge-resistant treatments used on computer touchscreens.
How long we consumers will have to wait for smudge-free touchscreens depends in part on the willingness of tech companies to get behind the research. Despite the computer makers knowledge of the research going on at MIT, none has provided funding, and licensing discussions are still at the beginning stages. With sufficient funding, McKinley says, he believes they could deliver a working, scalable, and cost-effective solution to touchscreen makers within two to five years.
Money is the limiting factor, McKinley says. Its a question of how much are we willing to pay; how much are we willing to add to the price for something for a smudge-free screen?
No big rush
The truth is, creating smudge-free screens isn't at the top of most manufacturers priority lists. Manufacturers typically see brightness, color saturation, and resolution or pixels per inch as their primary marketing issues for displays on tablets and smartphones, says research scientist Dr. Raymond Soneira, who developed the widely used DisplayMate testing utility.
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