Dynamic physical affordances for shape-changing and deformable user interfaces

Abstract

The world is filled with tools and devices designed to fit specific needs and goals, and their physical form plays an important role in helping users understand their use. These physical affordances provide products and interfaces with many advantages: they contribute to good ergonomics, allow users to attend to other tasks visually, and take advantage of embodied and distributed cognition by allowing users to offload mental computation spatially. However, devices today include more and more functionality, with increasingly fewer physical affordances, losing many of the advantages in expressivity and dexterity that our hands can provide. My research examines how we can apply shape-changing and deformable interfaces to address the lack of physical affordances in today's interactive products and enable richer physical interaction with general purpose computing interfaces. In this thesis, I introduce tangible interfaces that use their form to adapt to the functions and ways users want to interact with them. I explore two solutions: 1) creating Dynamic Physical Affordances through shape change and 2) user Improvised Physical Affordances through direct deformation and through appropriation of existing objects. Dynamic Physical Affordances can provide buttons and sliders on demand as an application changes, or even allow users to directly manipulate 3D models or data sets through physical handles which appear out of the data. Improvised Physical Affordances can allow users to squeeze, stretch, and deform input devices to fit their needs, creating the perfect game controller, or shaping a mobile phone around their wrist to form a bracelet. Novel technical solutions are needed to enable these new interaction techniques; this thesis describes techniques both for actuation and robust sensing for shape-changing and deformable interfaces. Finally, systems that utilize Dynamic Physical Affordances and Improvised Physical Affordances are evaluated to understand patterns of use and performance. My belief is that shape-changing UI will become increasingly available in the future, and this work begins to create a vocabulary and design space for more general-purpose interaction for shape-changing UI.