Applications that support touch displays overwhelmingly rely on visual feedback to let the user know what touch event occurred. Some applications support delivering an audio signal to the user, such as a click or beep, to acknowledge that a button or virtual key was pressed. However, in many touch interfaces, there is no physical feedback, such as a small vibration, to let the user know that the system detected a touch of the display.

Contrast this with the design of mechanical keyboards. It is an explicit design decision whether the keys are soft or firm to the touch. Likewise, the “noisiness” of the keys and whether there is an audible and physical click at the end of a key press are the result of explicit choices made by the keyboard designer.

As end devices undergo a few design generations of supporting touch interfaces, I expect that many of them will incorporate haptic technology, such as from Immersion, so as to deliver the sensation of the click at the end of a key press. However, I am currently not aware of how a digital touch interface can dynamically simulate different firmness or softness of the touch display, but something like the Impress squishy display may not be too far away.

Some other interesting possibilities for touch based information and feedback are presented in Fabian Hemmert’s video about shape shifting mobile devices. In the video he demonstrates how designers might implement three different types of shape shifting in a mobile phone form factor.

The first concept is a weight-shifting device that can shift its center of mass. Not only could the device provide a tactile feedback of where the user is touching the display, but it can be used to “point” the user in a direction by making it heavier in the direction it wishes to point. This has the potential to allow a device to guide the user through the city without requiring the user to look at the device.

The second concept is a shape-shifting device that can transform from a flat form to one that is raised on any combination of its four corners. This allows the device to extend an edge or taper a corner toward or away from the user to indicate that there is more information in the indicated direction (such as when looking at a map). A shape-shifting capability can also allow the device to be placed on a flat surface, say a nightstand and allow the device to take on a context specific function – say an alarm clock.

The third concept is a “breathing” device where the designer uses the shifting capabilities of the device to indicate a health state of the device. However, to make the breathing concept more than just an energy drain, it will need to be able to decide whether there is someone around to observe it, so that it can save its energy when it is alone.

The mass- and shape-shifting concepts hold a lot of promise, especially when they are combined together in the same device. It might be sooner than we think when these types of features are available to include in touch interfaces.

Tags: Haptics, Touch Sensing

This entry was posted on Tuesday, October 12th, 2010 at 1:44 pm and is filed under User Interfaces. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.