When multitudes of Windows 8 users start playing with newly purchased hardware in the coming weeks and months, they'll encounter an indignity that once afflicted only smartphone and tablet users: dirty, smudgy, fingerprint-riddled touchscreens.
Ah, yes, the dreaded smudge. It's a problem we've all come to grudgingly accept on mobile device screens, but PC users generally aren't so accepting of people touching—let alone leaving fingerprints on—their desktop displays.
If Microsoft executive Keith Lorizio has his way, some 400 million Windows 8 devices will be active by July 1, 2013. Lorizio was surely including nontouch legacy machines when he made this optimstic declaration last week, and Microsoft has already backed away from Lorizio's comments. But the fact remains that desktop computing is about to get very, very dirty.
So just what is the tech industry doing to head off the collision between PC screens and fingers? Or will desktop users simply resign themselves to a life where dirty screens become the new normal?
If we look to the mobile industry for answers, we see that accessory makers are taking the lead in fingerprint control, answering consumer demand for products that protect phones and tablets from not just smudges, but cracks.
Meanwhile, the hardware manufacturers and their touchscreen suppliers have so far not invested heavily in new science that might stop screen smudging. Rather, they're taking a much more measured, less expensive approach.
“Our impression is that smudge-proof touchscreens are still pretty far from becoming commercially available,” says IDC tablets and displays analyst Linn Huang. “Right now the most elegant solution available is the manufacturers including a free, small terrycloth to use to wipe the screen with each tablet they ship.”
Nor are computer manufacturers investing heavily in in-house research that might lead to an effective smudge-resistant surface. Instead, this type of research is happening in universities like Northwestern and MIT, and in various institutional research facilities around the world, such as the Max Planck Institute in Germany and GE Global Research.
Two approaches to resisting smudges
Researchers pursue two strategies for making better oleophobic screens (oleophobic literally means “lacking affinity for oils”). Some scientists try to advance the chemical treatment approach now used by Apple and others, while others work on applying new physical textures on screen surfaces, textures that are unfriendly to oil and liquid.
Apple was the first large tech brand to apply an oleophobic chemical treatment to the screens of a major product line. The glass screen of the iPhone 3GS was covered with an organic, carbon-based polymer that prevents oil from the skin from sticking to the screen. Instead, the oil (from the user's fingers, cheek, ear, or nose) stays bonded together in droplets, but not bonded with the screen.
Apple’s solution didn’t rid the phone of fingerprints and smudges very effectively, but Apple has stuck with its oleophobic surfaces. New iPhones and iPads ship with oleophobic screens. And the company has certainly invested in research on oil-resistant screens: In February 2011, Apple filed a patent on a special process for applying an oleophobic polymer to the surface of a touchscreen.
Physical screen texturing
The most promising research in oleophobic surfaces involves the physical texturing of screen surfaces. Last December, Max Planck Institute researchers published a paper in the journal Science saying that regular soot—the carbon residue released from a burning candle—can create a rough, oil-resistant surface.
The researchers coated a slide with candle soot, then covered the layer of carbon residue with a layer of silica structures and baked the whole thing at 1112 degrees Fahrenheit, which made the layer of soot transparent.
During tests afterward, the researchers found that oil and dirt particles were repelled by the surface, that they bounced right off the surface of the slide, and did not break apart and scatter about.
Not only did the surface seem to work exceptionally well against fingerprinting, but it was a relatively cheap and simple solution. The only problem was that the surface wasn’t very robust and stable and could easily be scratched off.
Hybrid approach holds most promise
The most promising attempts to create the transparent, oleophobic surfaces that touchscreen makers need use a hybrid approach. “Simply using chemicals will not get it done; what is needed is a dramatic combination of chemical treatment and texturing,” says Neelesh A. Patankar, professor of theoretical and applied mechanics at Northwestern University.
Patankar says (and others agree) that the research with the best chance of leading to a real nonsmudge touchscreen is a hybrid solution being developed by a pair of MIT researchers named Gareth McKinley and Bob Cohen.
The two began a project in the mid-2000s developing liquid-resistant surfaces for the Air Force, which wanted to make materials like O-rings resistant to liquids like jet fuel. Jet fuel, McKinely explains, is a liquid with “low surface tension,” which means, in very simple terms, that it forms droplets easily.
Liquids like fingerprint oil and sweat, as it happens, also have low surface tension, because they’re both full of bodily secretions like lipids and fatty acids, McKinley says. “This is why they are so hard to remove,” he says. “They want to spread over everything.”
The suggestion that McKinley’s and Cohen’s surface treatment might repel finger oil and sweat caught the attention of the computer industry. “After we released a couple of research papers in 2007 and 2008 describing our results, we immediately began getting calls from technology companies,” McKinley explains. Some in the tech industry saw in the research a possible opportunity to make smudge-resistant touchscreens.
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 doesn’t 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. “It’s 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.
But touchscreens, especially those for smartphones and tablets, have become a commodity whose main distinguishing feature is simply price. Device makers like Samsung, Dell, HP, and HTC play in an extremely competitive market where margins are squeezed to the limit. These companies are eager to pay lower and lower prices for touchscreens. So naturally the device makers and their touchscreen suppliers are in no hurry to introduce expensive new features—such as oleophobic texturing—to the screens.
IDC’s Huang believes that sooner or later one of the major touchscreen device makers will take the plunge and invest in and license an oleophobic technology that it believes is cost-effective. The other major brands will then follow suit to avoid the perception in the marketplace that they’re being left behind, he says.
Accessory makers try to fill the gap
Right now, it is the accessory makers that have a commercially viable solution to screen smudging. Smartphone and tablet makers can find a wide array of coverings for their devices, featuring different materials and different finishes that provide either a glossy, glass-like finish, or a smooth matte finish instead.
The most popular type of screen protectors appear to be thin plastic film overlays that cover the touchscreen, but are actually made of more complex polyurethane. Wrapsol makes film for a variety of smartphones, tablets, and laptops, and its Ultra screen covers feature three layers: a clear polyurethane resin on the top, a clear hybrid copolymer acrylic pressure-sensitive adhesive in the middle, and finally a film liner on the bottom that sticks to your device.
Wrapsol claims that each layer combines to create a cover that keeps your screen smudge free and that is shock absorbent—a great feature for mobile devices that are prone to drops, but less important for larger touchscreen PCs. Polyurethane covers shouldn’t affect the touch sensitivity of your screen, so you won’t have to apply more pressure or use it any differently. Other popular screen protectors made from polyurethane include Moshi’s iVisor and Zagg’s InvisibleShield.
Polyethylene terephthalate—more commonly known as PET—is also used in making screen protectors. BodyGuardz uses PET, which is a polyester-based plastic, to make its ScreenGuardz line to resist fingerprints and reduce glare.
The company actually uses different materials to protect against different elements: Its high-end cases are made from PET that protects against glare, scratches, and fingerprints, but the company’s Classic screen protector is made of clear vinyl and is not as strong. Vinyl covers are cheaper and meant to be disposable—just toss it and install a new one when it wears out. But PET and polyurethane covers are meant to be more long-lasting.
While mobile devices have plenty of accessories that are designed to help clean their touchscreens or to prevent them from getting smudgy to begin with, the market is a little far behind when it comes to touchscreen PCs.
Perhaps this is because such PCs aren’t quite mainstream enough to warrant their own line of screen protectors, or because the touch displays are easy enough to keep clean with basic household glass cleaners or good old distilled water.
TouchWindow makes a series of touchscreen overlays and protective films for desktop monitors, as does Posr.us, and these overlays will reduce fingerprints, but at a cost—your beautiful display might look less polished and dull. If you prefer the crisp look of the display, it might just be easier to clean it every once in awhile.