Force feedback and shape change provide unique interaction qualities that can be favourable for the design of more intelligent physical user interfaces, as communication revolves to a large extent around body language and gestures. Currently, there is a dearth of design tools which are needed to accelerate exploration of the design space of haptic and shape change in user interfaces, given the challenges associated with the haptic modality and the expertise that is required for the development of such interfaces. Design tools have the potential to improve the accessibility of these modalities as design material within HCI and facilitate exploration of the design space. In this studio, we will use the design tool Feelix to explore possibilities and opportunities for force feedback and shape change in actuated interfaces.

This paper presents an evaluation of DynaKnob: a dynamic rotary knob that uses the relationship between physical shape and haptic force feedback to provide feedback about its functionality. It has the ability to morph into four distinct shapes whilst providing dynamic haptic force feedback. We explore how shape change and haptic force feedback can improve interactions by evaluating the DynaKnob in terms of usability, user experience and performance. Additionally, we look at how interaction techniques are influenced by these modalities. Results indicate that multimodal cues provided by haptic force feedback and different shapes did not improve usability, since the visual feedback provided by the GUI dominated the evaluated context. However, both modalities had a positive effect on the user experience, and showed potential to improve the performance in terms of accuracy for non-visual interaction.

In the last decade, haptic actuators have improved in quality and efficiency, enabling easier implementation in user interfaces. One of the next steps towards a mature haptics field is a larger and more diverse toolset that enables designers and novices to explore with the design and implementation of haptic feedback in their projects. In this paper, we look at several design projects that utilize haptic force feedback to aid interaction between the user and product. We analysed the process interaction designers went through when developing their haptic user interfaces. Based on our insights, we identified requirements for a haptic force feedback authoring tool. We discuss how these requirements are addressed by 'Feelix', a tool that supports sketching and refinement of haptic force feedback effects.

Tabletop interactions can support various social activities such as collaborative review of dynamic sales information in the business setting or route planning with an interactive map among others. Sharing control between users of interactive surfaces can be difficult to ensure participation and efficiency for co-located contexts. We explore the differences between two modalities for interacting with a tabletop map including interactions with a voice assistant and tangible interactions with a shape-changing controller. To simulate a shared goal-oriented situation, we use the context of shared autonomous mobility and compare the tangible controller with voice input through simulated tasks of route planning and detours. The findings suggest that the most suitable interaction modality depends on user preferences, scenarios, and contexts. Tangible controls work well for communicating the state of the system and facilitating discussion, while voice can be more pragmatic and task oriented.

Despite the advantages of tangible interaction, physical controls like knobs seem to be disappearing from a wide range of products in our everyday life. The work presented in this paper explores how physical controls can become dynamic, in terms of both shape, and haptic force feedback. The paper contains two strands of work: First, we present a study that explores the relationship between haptic force feedback and different knob shapes, evaluating twelve distinct haptic stimuli in relation to six widely used knob shapes. Second, based on the insights collected in the study, we present the design of DynaKnob, a shape changing knob that can change between four different knob shapes. DynaKnob illustrates how dynamic content control, can be combined with dynamic shape and force feedback. Both the study and the design of DynaKnob contribute to understanding how adaptive physical interface controls could be designed in the future.

Force feedback and shape change are modalities with a growing application potential beyond the more traditional GUIs. We present two studies that explored the effect of these modalities on the emotional experience when interacting with an intelligent thermostat. The first study compared visual feedback, force feedback, and a combination of force feedback and shape change. Results indicate that force feedback correlates to experienced dominance during interaction, while shape change mainly affects experienced arousal. The second study explored how force feedback and shape change could communicate affective meaning during interaction with the thermostat through a co-design study. Participants designed the thermostat behavior for three scenarios supporting energy savings. Results suggest that despite their abstractness, force feedback and shape change convey affective meaning during the user-system dialogue. The findings contribute to the design of intelligible and intuitive feedback.

Although interfaces can adapt to users' behavior only little empirical evidence has been reported about their capability to influence people's emotions. The goal of this study is to explore the influence of haptic force feedback on the emotional experience in a linear sliding movement. We varied force feedback behaviors designed for a motorized slider in a controlled experiment. The slider presented three behaviors, named as counteractive, assistive, and no behavior while participants were exposed to affective imagery varying in valence. The results showed that under different emotions (positive, negative, neutral), people experience small differences in dominance and valence between the force feedback behaviors. A counteractive force feedback seems to increase the feeling of control regarding unpleasant stimuli, while providing an assistive force feedback reduced the level of dominance in case of pleasant stimuli. Our study contributes new understanding of how adaptive feedback influence user's emotions to support design in this field.