Smartphones are becoming larger, mainly because bigger screens offer a better experience for viewing content. One drawback of larger screens is that they make single-hand interactions difficult because of hard to reach touch targets and of the need to re-grip the device, both factors significantly reducing their usability. Flexible smartphones offer an opportunity for addressing this issue. We first set out to determine the use of common single-hand mobile interactions through an online survey. Then, we designed and evaluated one-handed deformable gestures that offer the potential for addressing the finger reach limitation on large smartphones. We identified that the top right up bend and the center squeeze up gestures are the fastest and preferred gestures. We found no hand preference, which indicates that the gestures could be implemented to fit the needs of a wider range of the population, instead of favoring right-handed users. Finally, we discuss the impact on deformable gestures on one-handed interactions issues.

We evaluated the use of rich tactile feedback in the task of scrolling through a long list of items. We used a hand-held device having a tactile transducer that could provide sensations with temporal and spatial content. These capabilities were put to use in an interaction metaphor where input and tactile feedback were tightly coupled. We measured time- to-target and error rates, but also measured the time spent by participants to look at the screen. We found a 28% decrease of reliance on vision when tactile feedback was enabled.

We present a haptic wristwatch prototype that makes it possible to acquire information from a companion mobile device through simple eyes-free gestures. The wristwatch we have built uses a custom-made piezoelectric actuator combined with sensors to create a natural, inconspicuous, gesture-based interface. Feedback is returned to the user in the form of haptic stimuli that are delivered to the wrist. We evaluated the capabilities and limitations of our prototype through two user experiments. One experiment verified that the apparatus could be used as a tactile notification mechanism. The other experiment assessed the feasibility of using a cover-and-hold gesture on the wristwatch to obtain numerical data tactually. Results from the numerosity experiment and feedback from participants prompted us to redesign the cover-and-hold gesture to provide users with additional control over the interaction. We qualitatively evaluated the redesigned interaction by handing the prototype to users so that they could use it in a realistic work environment. Taken together, results from the experiments and the validation process indicate that a wrist accessory can be effectively used to perform discreet, closed-loop, eyes-free interactions with a mobile device.

This paper describes the design, construction, and initial evaluation of a handheld information device that supports combined tactile and graphical interaction. The design comprises a liquid crystal graphic display co-located with a miniature, low-power, distributed tactile transducer. This transducer can create electronically-controlled lateral skin deformation patterns which give the sensation of sliding over small shapes. It is integrated within a slider mechanism to control scrolling. It also functions as a detent when pushing on it. Tactile feedback and the combination of visual and tactile feedback in a mobile context enable the development of new functions, such as multimodal navigation within large graphic spaces

Mobile interaction can potentially be enhanced with well-designed haptic control and display. However, advances have been limited by a vicious cycle whereby inadequate haptic technology obstructs inception of vitalizing applications. We present the first stages of a systematic design effort to break that cycle, beginning with specific usage scenarios and a new handheld display platform based on lateral skin stretch. Results of a perceptual device characterization inform mappings between device capabilities and specific roles in mobile interaction, and the next step of hardware re-engineering.

When a progressive wave of localized deformations occurs tangentially on the fingerpad skin, one typically experiences the illusion of a small object sliding on it. This effect was investigated because of its potential application to the display of Braille. A device was constructed that could produce such deformation patterns along a line. Blind subjects' ability to read truncated Braille characters (‘○○’, ‘○•’, ‘•○’, and ‘••’) using the device was experimentally tested and compared to their performance with a conventional Braille medium. While subjects could identify two-character strings with a high rate of success, several factors need to be addressed before a display based on this principle can become practical.