In this paper, we report on an investigation of Fitts' law using flexible displays. Participants performed a one-dimensional targeting task as described by the ISO 9421-9 standard. In the experiment, we compared two methods of bend input: position control and rate control of a cursor. Participants performed the task with three levels of device stiffness. Results show that bend input is highly correlated with Fitts' law for both position and rate control. Position control produced significantly higher throughput values than rate control. Our experiment also revealed that, when the amount of force applied was controlled, device stiffness did not have a significant effect on performance.

ReFlex is a flexible smartphone with bend input and active haptic feedback. ReFlex's features allow the introduction of sensations such as friction or resistance. We report results from an experiment using ReFlex in a targeting task, as well as initial users' reactions to the prototype. We explore both absolute and relative tactile haptic feedback, paired with two types of bend input mappings: position-control and rate-control. We observed that position-controlled cursors paired well with relative bend feedback, while rate-controlled cursors paired well with absolute bend feedback to indicate targets. We also explored an eyes-free condition. Results suggest that while eyes-free, haptic feedback conditions were more error-prone than visual-only conditions, the size of the error was relatively small, and users were able to complete the task in all cases. We present two application scenarios that take advantage of the unique input and output modalities of ReFlex and discuss its potential for within document navigation.

Mobile devices can provide people with contextual information. This information may benefit a primary activity, assuming it is easily accessible. In this paper, we present DisplaySkin, a pose-aware device with a flexible display circling the wrist. DisplaySkin creates a kinematic model of a user's arm and uses it to place information in view, independent of body pose. In doing so, DisplaySkin aims to minimize the cost of accessing information without being intrusive. We evaluated our pose-aware display with a rotational pointing task, which was interrupted by a notification on DisplaySkin. Results show that a pose-aware display reduces the time required to respond to notifications on the wrist.

We present FlexView, a set of interaction techniques for Z-axis navigation on touch-enabled flexible mobile devices. FlexView augments touch input with bend to navigate through depth-arranged content. To investigate Z-axis navigation with FlexView, we measured document paging efficiency using touch, against two forms of bend input: bending the side of the display (leafing) and squeezing the display (squeezing). In addition to moving through the Z-axis, the second experiment added X-Y navigation in a pan-and-zoom task. Pinch gestures were compared to squeezing and leafing for zoom operations, while panning was consistently performed using touch. Our experiments demonstrate that bend interaction is comparable to touch input for navigation through stacked content. Squeezing to zoom recorded the fastest times in the pan-and-zoom task. Overall, FlexView allows users to easily browse depth arranged information spaces without sacrificing traditional touch interactions.