ExpanDial: Designing a Shape-Changing Dial
Proceedings of the 2018 CHI Conference on Human Factors in Computing Systems, CHI’18. (acc.25%) [pdf]
KnobSlider is a shape-changing device that changes between a rotational knob and a linear slider to accommodate users’ needs. In the situation depicted (a) a sound engineer uses it as a slider to coarsely control a sound volume. He then presses the central button to trigger the change into (b) a low control-display (CD) gain knob, and (c) he can use it for fine adjustment.
Physical controls are widely used by professionals such as sound engineers or aircraft pilots. In particular knobs and sliders are the most prevalent in such interfaces. They have advantages over touchscreen GUIs, especially when users require quick and eyes-free control. However, their interfaces (e.g., mixing consoles) are often bulky and crowded. To improve this, we present the results of a formative study with professionals who use physical controllers. Based on their feedback, we propose design requirements for future interfaces for parameters control. We then introduce the design of our KnobSlider that combines the advantages of a knob and a slider in one unique shape-changing device. A qualitative study with professionals shows how KnobSlider supports the design requirements, and inspired new interactions and applications.
Video of the working prototype
We also share the instruction of how to build the KnobSlider by yourself on Instructables. We wish many people build it and spread the idea of shape-changing interfaces!