One problem with touch technology, especially in today's germ-phobic society, is that the touch of the average human fingertip leaves a visible residue. Even recently cleaned hands exude perspiration and oil, due to oil-producing glands located in the fingertips. When fingers come into contact with any relatively smooth surface, such as a tablet screen, the friction releases the oil.
The issue is primarily aesthetic – most people do not like smudges on their personal devices. In the case of public touch screens – supermarket checkout monitors and the like – the sight of other people's fingerprints is a turn-off for many users. Beyond the aesthetics, fingerprint smudges can interfere with actual viewing under conditions such as bright sunlight. This problem is more significant when multi-layer optical coatings are applied to the touch screens, usually to enhance high-ambient-light readability. Then, the presence of fingerprints can cause unattractive bluish smudges that can make the device almost unreadable. For military or medical applications, fingerprints that affect readability in high ambient light are a serious concern.
"Anti-fingerprint technology is currently an interesting topic," says Jennifer Colegrove, a vice president with DisplaySearch, "because it is rumored that the iPad 2 will have it." And where Apple goes, continues Colegrove, other products are likely to follow.
It is possible to fingerprint-proof your personal mobile devices now – from phones to tablets to larger displays – with aftermarket films available from companies such as SGP Steinheil, UniPixel, Wrapsol, and ZAGG. A SGP Steinheil "ultra-oleophobic" screen protector for an iPhone 4 can be had for about $15 on Amazon. But in the future, according to Colegrove, expect to see more such protection built into device screens at the factory, especially if the iPad 2 rumor is true.
How effective or long-lasting the built-in anti-fingerprint technology will be is unknown. To date, most of the aftermarket films have a limited lifespan in terms of effectiveness, and many add a matte look and rougher texture to the display – a plus for some users and a negative for others.
The way most available anti-fingerprint technologies work is through surface tension that spreads the oily deposits on contact. Normally, these tiny drops of oil and water form spherical shapes that are apparent on the surface of screens. With anti-fingerprint technology, "The oil spreads out so you do not see it," says Colegrove – small comfort to the hygiene-obsessed, but a big step in terms of a nicer looking and more readable screen.
Another possible way to approach the fingerprint problem, notes Colegrove, is to remove the physical contact from the equation altogether with "touchless" touch technology such as that being developed by Microsoft or Elliptic Labs.
New Touch Products
Tyco Electronics recently introduced the Elo TouchSystems 2242L open-frame touch monitor, available with the company's IntelliTouch Plus Multi-Touch surface-acoustic-wave touch technology. It is Elo's newest monitor that is compatible with the Windows 7 operating system's additional qualifications (AQ) for multi-touch functionality. The wide-aspect-ratio display is designed to provide stable, "drift-free" operation with superior image clarity, resolution, and light transmission, as well as accurate touch response. Possible applications for the 2242L include point-of-sale (POS), point-of-service, digital signage, loyalty systems, kiosk information systems, light industrial shop-floor automation, and home control.
3M has extended its line of transparent conductors with the new 3M Patterned Transparent Conductors, designed for use in thinner, lighter consumer-electronic devices for a variety of applications including projected-capacitive touch sensing.
According to 3M, the conductors combine many of the advantages of glass-based projected-capacitive sensors, such as fine conductive feature width and low sheet resistance, with the thinness and weight advantages of a film-based material. The material supports curved and narrow bezel touch-sensor designs, increasing the effective display area of smartphones and tablet devices.
3M Transparent Conductors are also available as Unpatterned Transparent Conductors for EMI shielding applications.