Tactile feedback gives us a meaningful way to experience and know our environment. Touch can provide a powerful understanding, allowing us to discern things such as shape, texture, volume, density or relationships between objects. Current use of tactile stimuli in touch screen devices is primarily addressed through haptic feedback delivered through vibration. 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 also one day also be able to mimic more complex and subtle surface texture.
A well-known method of providing information through touch is braille. Braille provides discrete tactile patterns that form syntax and can even represent information as a logogram, which is a visual symbol that represents a word or phrase. But braille is a one to one correlation that is consumed as relatively specific meaning. The application of complex surface textures on touch screen devices might be better suited to imply meaning through relationships.
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 to infer meaning from a tactile difference between areas on the screen. 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 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, alignment, grouping, hierarchy, and labeling to draw attention and give meaning to distinct elements and sets of information.
What if a calendar app presented days where nothing was planned as a smooth surface and days that had events were provided with a texture? What if binary choices had different textures? Or what if your application icons all had distinct surfaces that allowed you to pick one by touch alone? A sight impaired user might then be able to engage with their desired task and perhaps voice commands could facilitate further interaction with the app, or differences in tactile sensations themselves could be used to deliver meaning. Touch can make information more accessible on surface devices. And tactile qualities could also be used to support and enhance visual elements, skeuomorphic or not.
The possibilities for tactile feedback on touch screen devices are likely as varied and nuanced as tasks themselves. Of course, each implementation decision 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 rich and meaningful experiences with our interactive digital devices by more fully employing the power of touch.