Thanks to a handful of emerging technologies, virtual touchscreen keyboards are getting closer to the feel of real electromechanical keyboards. Enhancements such as tactile feedback and surfaces that change to mimic physical keys could eventually redefine the virtual keyboard experience for millions of users of devices ranging from smartphones to tablets and touchscreen PCs.

Will these improvements be enough for the virtual keyboard to entirely displace the electromechanical keyboard? Maybe not for folks old enough to have used an IBM Selectric typewriter, whose keyboard served as the model for early computer keyboards, but improved virtual keyboards may be just fine with a new generation of users for whom big clunky keyboards are so yesterday.

On smartphones, virtual keyboards have largely replaced the more expensive electromechanical keyboards, with a few notable exceptions such as BlackBerries and QWERTY texting phones.

On the PC front, we've seen concept laptops with two displays for some time now, usually with the idea that the bottom screen can be used as a virtual keyboard when needed. And PC vendor Acer recently announced a dual screen notebook as well, though such devices are still far from mainstream. On PCs used for intensive content creation, however, the physical keyboard is unlikely to go away entirely, although an integrated virtual keyboard is likely to become a complementary component.

The real battleground may be over tablet computers. As users of devices such as the iPad progress from web surfing and content consumption to a mix of consuming and creating content, demand for better keyboard performance will increase.

Today most iPad users who buy productivity software also reach for Apple's optional external keyboard, says the sales manager at one Apple Store, and about 40% of those who come into that store for iPad training at the Genius Bar bring in or walk out with external keyboards. Tomorrow, though, the touch screen may just be good enough.

Good vibrations

Next generation touchscreen devices will embed more haptics, or touch-based feedback, into virtual keyboards. Haptic technology uses targeted vibrations to deliver tactile feedback that can vary in frequency, direction and intensity to simulate a key click or to present different surface textures within discrete areas of the display.

When combined with visual and audio input, those finely tuned vibrations, which may be generated by mechanical actuators or electrostatic charges, can fool your brain into thinking that you've just pressed a physical key.

"A lot of companies are really getting into haptics, [using] source feedback and a sense of touch to try to replicate a keyboard on a display," says Bruce Gant, a mechanical engineer at Product Development Technologies, which integrates touchscreens into cell phones and other devices for manufacturers. "If people really get that down and nail that experience, [virtual keyboards] could replace mechanical keyboards on laptops."

Immersion, which has developed a product that uses a mechanical actuator to deliver haptic feedback on a touch screen, says the next generation of haptics will be able to replicate the feel of key travel as well as the keyboard click of a mechanical keyboard. "You don't get the actual travel of your finger, but you can get much more of it back," says Dennis Sheehan, Immersion's vice president of marketing.

But simple tactile feedback isn't enough for touch typists. That's because the feel of a real keyboard goes beyond the limited range of surface textures that haptics can provide. For example, a touch typist continuously realigns his fingers by sensing the edges of each key as he types. The gaps between the keys and the bumps on the J and F home keys let him find the correct position by feel.

"On a touch screen, you lose all of that surface feel," says Mike Levin, a vice president at haptics technology provider Pacinian.

Even with haptics technology, touch typists won't be able to feel a tactile ridge along the edge of virtual keys, as they would on physical keyboards. But Pacinian's pressure-sensitive haptics can provide a different sensation for the home keys to differentiate them from the other keys on the keyboard, Levin says.

Unfortunately, today Pacinian's technology can only do that for one position at a time: You can sense a different pulse for the J or the F position, but not for both at once. Pacinian is working on a solution for that.

Force sensing, surface deforming

A bigger problem is that on today's capacitive touch screens, which detect your fingers' electrical conductivity as you touch the screen, you can't touch the keyboard to orient your fingers without activating the keys. On a physical keyboard, you touch the keys to determine position and then press down on them to type. That's missing on touchscreens, which can sense a touch, but not the force with which it is applied.

Pacinian is also working to improve that. "The stuff we're working on adds a force sensor to improve the experience," says Levin. In this way, a user could use touch to find a button and then increase pressure to select it.

If Pacinian can provide feedback for both home key positions and use force-sensing technology to allow users to orient their fingers without activating keys, a virtual keyboard might be good enough for hunt-and-peck typists. But it's still not going to be enough for high speed touch typists who are accustomed to rolling along at 100 to 150 words per minute.

"You don't have those surface features to locate your fingers on," Levin says. So users would still have to look at the keyboard as they adjust their finger positions.

Pursuing a moving target

In trying to offer better tactile response for typists, virtual keyboards are following a moving target. The essential characteristics of the electromechanical keyboard have changed dramatically over the past 20 years, says David Hill, vice president of design at Lenovo.

The keyboard that graced the original IBM PC 5150 in 1981 was designed to mimic the feel of an IBM Selectric typewriter, which in turn was designed to mimic the feel of earlier typewriters, from the QWERTY layout to the long key "travel" that allowed the typebars (thin arms with letters on them) to strike the platen (the roller on which the paper was fed).

Early electric typewriters offered a loud response and strong "force curves," measures of the pressure needed to depress a key and the speed at which it returns to its original state. Keyboards weren't designed for ergonomics and performance so much as to be compatible with what was already familiar to typists of the day.

"Over time, those have been transitioned to keyboards that have less sound, less clickety clackety and less travel," Hill says.

Today's keyboards mount mechanical keys over electric sensors, most often a two-layer membrane with a suspension layer in between. When the user pushes down, a key depresses the layers, making a contact.

While the membrane itself has a certain amount of spring to it, the device may also include a spring or in the case of Lenovo's ThinkPad notebook line, a scissoring mechanism that snaps the keys back in place after the user depresses them. Key travel can be as short as 2mm, about half that of early designs.

Keyboard preferences are very much generational, so the acceptability of virtual keyboards depends on the user's frame of reference. The attributes that were important to a typist familiar with the manual typewriters of 1940s are different from what's important to a secretary who used a Selectric in the 1960s. Today's young users have an entirely different perspective. Most are already familiar with touchscreen keyboards and have never seen or used an electric typewriter, never mind a manual one. And most would find the keyboard that shipped with the original IBM PC to be clunky, says Hill.