The current generation of smartphones built using Immersion's designs is limited to a few basic vibrational patterns capable of emulating a button click or a low-frequency woofer pattern to augment the bass sounds of a ring tone.
But Immersion and other haptics vendors are developing more sophisticated techniques that finely tune vibrational frequencies to simulate different textures on the screen surface, and to target specific areas of the screen so that, for example, only the finger touching a "depressed" key on a virtual keyboard feels a click sensation.
Immersion's newest "high-definition" system, called TouchSense 5000, use piezo actuators -- ceramic devices that move when current is applied -- to offer even more refined sensations. The company says that, by fine-tuning the vibrations in combination, its newest technology can cause the user to perceive that he's feeling different textures as he slides a finger over a display's surface, or it can create the sensation of motion, which could be useful for apps that involve the use of a virtual slider control.
The technology allows for vibrations that "more closely mimic" real-life sensations, according to Immersion. "For example, we have a pinball game application that when the ball travels over a metal grate, the haptics effects make it feel like the ball really is traveling over a metal grate," Sheehan says.
Even more refined sensations are possible. The combination of vibration and friction patterns required to emulate the feel of a wood-grain surface can be simulated using electromechanical actuators, Sheehan says. But the technology is costly to use in a smartphone. "We can't drop that into a $200 cell phone today, but it's coming," he predicts.
Therein lies the rub. TouchSense 5000 is available now, and Sheehan says several manufacturers are "actively evaluating" it. But no manufacturers have announced phones that use it or indicated when such devices might become available.
Immersion is also working with a partner to integrate its haptics technology with a "deformable surface" technology that allows sections of a touch screen to rise up or sink down in response to an electrical stimulus. For instance, individual keys could rise up and out of the screen's surface on top of the image of a virtual keypad or keyboard, further enhancing tactile feedback, Sheehan says. However, such shape-shifting display technology is still in the early stages of development.
Haptic designs based on actuators work well on small smartphone displays, but the component and drive electronics required are expensive to manufacture for the larger screens used in tablets and laptops.
Start-up Pacinian Corp. is working on a more scalable haptic technology, called surface actuation, that creates vibrations by applying an electrostatic field to two conductive surfaces that cover the touch screen. When activated by the touch of a finger, the top surface pulls away from the user's finger.
A force sensor can also detect the amount of pressure the user is applying to the screen and vary tactile feedback accordingly. Pacinian plans to leverage that capability to develop an ultrathin laptop keyboard that will still have low-profile physical keys but will be only half as thick as a traditional electromechanical keyboard.
Pacinian's technology can scale upward, but its systems are too large to fit into the small smartphone screens where Immersion dominates. Instead, the company has focused on developing tablet- and laptop-size screens of between six and 15 inches; it hopes to launch its first products, designed for use in industrial and medical systems, in the first half of this year, with products for the consumer market due by the first half of 2012.
Like Immersion's technology, Pacinian's haptics technology can vary vibrational frequencies to create the sensation that a touch-screen surface has a texture. However, Pacinian isn't "as focused on trying to create hundreds of different feels," says Mike Levin, vice president of business development at Spokane, Wash.-based Pacinian.