Tactile feedback gives us a rich and visceral way to experience and know our environment. Touch can provide a powerful understanding, allowing us to discern things such as shape, texture, volume, density, and relationships between objects.
Current use of tactile stimuli in touch screen devices is primarily addressed through vibration; haptic feedback. Research has also produced surfaces that are able to physically distort to allow the sensation of raised buttons and edges. It’s not unreasonable to think that touch screen devices might one day be able to mimic more complex and subtle surface texture.
Meaning is ultimately determined by context. The meaning of one thing is determined by its relationship to other things. The use of texture on a touch screen device could allow users another facet of understanding and context. If you’re fumbling in the dark for your keys you know when you’ve found them because of the way they feel, unless of course you’re looking for them in a roomful of keys. Then the ability to discern your particular set of keys in a roomful of keys is greatly diminished because there is very little difference in the environment; definition and contrast serve to highlight. This is the same principle we employ when we organize visual information on a screen. We use elements like white space, color, alignment, grouping, and hierarchy to draw attention and give meaning to elements and sets of information.
Touch can make information more accessible on surface devices. A sight impaired user might be able to complete a task through touch alone. Surface features could also be utilized as elements of a tactile language. These qualities could also be used to support visual elements, skeuomorphic or not.
The possibilities for tactile feedback on touch screen devices are likely as varied and nuanced as the tasks themselves. Of course, each implementation would have to be considered within its own need and design constraints, just like any other smart design element.
Our sense of touch has served us well since we’ve been sentient beings. There is no reason to think that we won’t be able to provide contextually rich and meaningful experiences with our interactive digital devices by more fully employing the power of touch.