Using Haptics to Address Mobile Interaction Design Challenges: Protoyping and User Evaluation with a Handheld Tactile Display
by Joseph Luk
Current user interfaces for mobile and handheld computing platforms
principally offer user interaction through the visual and auditory modalities.
However, mobile devices are often used in contexts where vision and hearing are
impaired. At the same time, more and more functionality is being layered upon
mobile devices, while the physical size of the display and keypad has remained
small. This limits the rate of information that can be exchanged between the
user and the system, and poses an interaction design challenge. Haptics offers a
potential solution by providing an additional modality that is also especially
well-suited to the demands of
portable, personal devices that are in contact with the user's skin.
In this work we identify ways that interaction through the sense of touch can
enhance mobile user interfaces. We describe the synergistic process of design of
user interaction concepts and novel handheld tactile display hardware based on
the principle of piezoelectric-actuated lateral skin stretch. Following the
realization of the prototype hardware, we performed perceptual characterization
studies to determine the expressive capabilities of the new device in the hands
of a human user. Informed by the results from the user studies, we built and
tested a handheld browser application with tactile enhancement. The results of
user testing with the browser application suggest that directional tactile
stimulation alone is not sufficient to enhance performance in spatial
navigation; however, by conducting a full iteration of a user-centred design
process in haptics, we have provided a case study to inform future development
efforts, a flexible platform for prototyping, and an indication of promising
future directions for using haptics to solve mobile interaction design
challenges.