Soft robotic actuators can create new uses and expressions for tangible and embodied interaction. Hydrogels, popular in soft robotics for their reversible shape-changing properties, often require technical expertise and specialized laboratories for fabrication, limiting rapid iteration. Additionally, aesthetic and form-giving qualities important to designers are often overlooked. This pictorial presents Aqua-Morph, an accessible design method for fabricating 3D-printed hydrogel-based structures that self-actuate in water. Our contributions are twofold: (1) a Design Manual outlining the fabrication pipeline using Fused Deposition Modeling (FDM) 3D printing with digitally adaptable parameters for creating flexible actuators, and (2) a Tangible Movement Library of shape-changing hydrogel structures to empower designers, creative roboticists, material scientists and engineers in creating tangible interactions.

The speculation of alternative relationships between humans and nonhumans is a crucial element of examining our dominating stance towards nature amidst the ongoing environmental crisis. The notion of designing for interdependence challenges this status quo, focusing on a local ecosystem and embedding carefully crafted artefacts to foster more-than-human relationships. The presented work engages with the intricate interdependence of bees, artefacts, time and location through an ongoing case study of designing with and living with red mason bees (Osmia bicornis). Unpacking the first author's design journey, we elucidate how attentive observations of the garden and engagement in activities such as the making of a beehouse have mobilized caring for the local ecosystem. With our focus on relationships emerging from situating oneself in a location for multispecies cohabitation, our research describes the dynamics of sharing resources between humans and nonhumans and its potential as a repertoire of more-than-human design.

The advancement of automated driving technologies is fundamentally transforming the relationship between humans and vehicles, shifting from direct control to a more collaborative dynamic. Consequently, the design of in-vehicle Human-Machine Interfaces (iHMIs) is becoming increasingly intricate, focusing on aspects beyond mechanics and ergonomics towards enriched interaction and enhanced user experience. This shift has prompted research efforts to explore and advance iHMI concepts. Despite the iterative nature of design and its role in knowledge creation, our high-level understanding of the design processes utilised in iHMI development remains limited. To provide a comprehensive overview, this paper presents a scoping review of 324 papers (2013—2023) focused on the design underpinnings of iHMI development. Our review presents a categorisation of study goals and a detailed classification of five key stages within the design process. Based on these analyses, we discuss the influence of design and identify potential avenues for future research on iHMIs.

Shape-changing interfaces have been critiqued for not being sustainable despite their promising opportunities for tangible interaction. Incorporating nature inspired passive actuation mechanisms with embedded responsiveness can offer benefits for shape-changing interfaces. We introduce chitosan, a widely available biodegradable and humidity-responsive actuator that absorbs moisture from air and undergoes shape changes in response to fluctuations in humidity. Through explorative yet systematic material driven research through design, we uncover the utility and accessibility of chitosan as a reversible actuator to enable interactivity. We present the characterization of a variety of responsive structures made from chitosan films, combined with a variety of substrates. Outcomes from a generative session with designers/engineers from diverse backgrounds, provided insights into experiential properties and possible applications. We conclude with early prototypes that hold potential for wearables, haptics, self-assembly, and data-physicalization.

Various studies demonstrated how to enrich edible materials with interactivity and shape-change using digital technologies such as 3D printing. We illustrate a collaborative and iterative process of developing a dish for two-Michelin starred restaurant ALCHEMIST in Copenhagen involving designers, material scientists, and chefs. They combined expertise in creative technologies, material behavior, and culinary arts to create novel dining experiences. Through a playful experience workshop, participants generated ideas to incorporate shape-changing food materials into their dishes. Digital prototyping technologies combined with material experiments resulted in an edible flower that through transforming petals becomes a tartelette when in contact with low or high pH solutions. We contribute a vision on how interactive dining experiences can be enriched with material-driven explorations, digital technologies, and experience design methods to create novel opportunities for human-food interaction. We reflect on the role of interaction designers when collaborating with chefs, and material scientists towards achieving this vision.

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.

Since the divide between nature and society, humans have objectified nature. This continuing separation has corrupted the relationship with our natural habitat. While various design research projects bring elements of nature into our cultivated environment, most incorporate nature as a separate entity. Although integrative collaborations with nature can be found in interactive projects designed from non-anthropocentric perspectives, they are not specifically aimed to connect humans with nature. We argue that the same forces that shape our natural habitat allow us to be closer to nature and propose the participation of natural phenomena as strong concept for the design of interactive systems. To illustrate this concept, we present Flare, a silk dress embroidered with dandelions made up of LED's which react to wind movements. With Flare as an evocative object, we draw parallels between existing theories and explore opportunities for designers to create interactions which help us to reconnect with nature.

A rising number of HCI scholars have begun to use materiality as a starting point for exploring the design's potential and restrictions. Despite the theoretical flourishing, the practical design process and instruction for beginner practitioners are still in scarcity. We leveraged the pictorial format to illustrate our crafting process of Puffy, a bio-inspired artifact that features a cilia-mimetic surface expressing anthropomorphic qualities through shape changes. Our approach consists of three key activities (i.e., analysis, synthesis, and detailing) interlaced recursively throughout the journey. Using this approach, we analyzed different input sources, synthesized peers’ critiques and self-reflection, and detailed the designed experience with iterative prototypes. Building on a reflective analysis of our approach, we concluded with a set of practical implications and design recommendations to inform other practitioners to initiate their investigations in interactive materiality.

In recent studies researchers have developed compelling and exciting shape-changing food (SCF) materials. Unfortunately, the adoption of SCFs in culinary practice is still complex. We present a research-through-design exploration of a novel SCF material that can be developed in restaurant kitchens using everyday kitchen appliances with the only addition of a commercial desktop 3D food printer. Our lightweight process involves the preparation of edible paper, which can be folded into origami shapes and is actuated through the addition of an acidic liquid. We facilitated participatory sessions with five chefs in their restaurants and evaluated our material. Our qualitative study contributes design guidelines on how to incorporate SCFs into chefs’ everyday culinary practices. Building on the chefs’ perspectives of our material and its culinary potential we conclude with a speculation of how SCF materials could enable novel multi-sensory and interactive food experiences.

Interactive textiles embed sensing and actuating capabilities in their fibers and structure. Adoption of interactive textiles is complex requiring a combination of competences or collaboration between interaction designers, textile designers and textile engineers. These disciplines are typically organized in separate and unconnected departments, using different vocabularies, and requiring different information. Through focus groups with interaction designers, and interviews with experts from the three domains we developed the Interactive Textile Library (ITL). The ITL is a multi-disciplinary tool combining physical samples and a digital platform showing material characteristics, experiential qualities, interactive technology, manufacturing process and support to create and hack the samples. The ITL was evaluated with professional designers who valued the physical samples and videos. Results provide recommendations for researchers developing interactive textile material libraries that could facilitate incorporation of interactive textiles in design practice and reduce fabrication time of prototypes.

Expressivity is frequently recurring as a term in HCI, but it is often approached from different perspectives. Affective computing prompted research into emotional expressivity, and with technology becoming more ubiquitous and tangible, the opportunities for expressive behaviors towards systems as well as the expressivity of systems increases. By analyzing exemplar research-through-design cases and a literature survey on the use of expressivity in interaction, we discuss how different perspectives and concepts contribute to understand expressivity in interaction. We integrate these perspectives and make them operational for interaction design by creating a framework including design considerations such as freedom of interaction, action-perception loops, multimodality, subtlety, ambiguity, skill development and temporal form. The framework is a result of a mixed-method approach including a review of existing definitions and scholarly artefacts, and a systematic literature review to identify design cases including an analysis of these design cases. We finally illustrate how the framework has been used to inform the design of a shape-changing soft-robotic interface. As a result, we contribute an integrated framework on how to design for expressivity in 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.

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.

Haptic feedback has frequently been proposed as a means to support eco-driving behaviour. While force and vibrotactile feedback have proven to be effective and safe approaches, no studies were found that assessed the user experience of different feedback designs. We describe the design of six haptic effects which were implemented in a custom designed accelerator pedal. The user experience of three effects (linear force increase, bump and pulse) were assessed in a driving simulator and compared to a baseline with no feedback. Results show that the haptic pedal effects were rated positively on attractiveness, dependability, stimulation and novelty. The pulsating effect scored significantly lower on attractiveness and dependability but highest on the novelty. Qualitative results suggest that combining a bump and pulse could increase the positive experience of a haptic pedal. Consequently, we argue for more experiential approaches to haptic feedback design in accelerator pedals.

Shape-changing interfaces have emerged as a new method for interacting with computers, using dynamic changes in a device's physical shape for input and output. With the advances of research into shape-changing interfaces, we see a need to synthesize the main, open research questions. The purpose of this synthesis is to formulate common challenges across the diverse fields engaged in shape-change research, to facilitate progression from single prototypes and individual design explorations to grander scientific goals, and to draw attention to challenges that come with maturity, including those concerning ethics, theory-building, and societal impact. In this article we therefore present 12 grand challenges for research on shape-changing interfaces, derived from a three-day workshop with 25 shape-changing interface experts with backgrounds in design, computer science, human-computer interaction, engineering, robotics, and material science.

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.

The analog Hall-sensor grid, GaussSense, is a thin-form magnetic-field camera technology for designing expressive occlusion-free, near-surface tangible interactions on conventional portable displays. The studio will provide hands-on experiences that combine physical designs and the GaussSense technology. Through a series of brainstorming and making exercises, participants will learn how to exploit natural hand and micro interactions through designing the expressions and affordances of physical objects, and know how to utilize physical constraints to provide additional kinesthetic awareness and haptic feedback. The exercises will be including form-giving, electronic prototyping, and hacking physical toys that are prepared by either the organizers or participants.

Despite an increasing number of examples of shape-changing interfaces, the relation between users' actions and product movements has not gained a great deal of attention, nor been very well articulated. This paper presents a framework articulating the level of control offered to the user over the shape change. The framework considers whether the shape change is: 1) directly controlled by the user's explicit interactions; 2) negotiated with the user; 3) indirectly controlled by the users actions; 4) fully controlled by the system. The four types are described through design examples using ReFlex, a shape-changing interface in the form of a smartphone. The paper concludes that shape-changing interfaces tend to assign the control to either the user or the underlying system, while few (e.g. [16,28]) consider sharing the control between the user and the system.

Technologies for shape-changing user interfaces are rapidly evolving, but our understanding of the design space of such interfaces is still limited. We report a repertory grid study that aims to describe the design space from the users' point of view by eliciting personal constructs about shape-change. The study is based on six similar-sized, shape-changing artifacts that combine simple sensing of users with actuation that change volume, texture, and orientation. Our results show that the 18 respondents distinguish artifacts on dimensions that differ from those of most models of shape change. For instance, they characterize shape-change in terms of personality, territoriality, and state of mind, in addition to more common categories such as appearance and product properties. We discuss how the dimensions derived from users might be used to design shape-changing interfaces.

To counteract the increased tendency in skill learning addressing our cognitive abilities we discuss an opportunity on how performance skills can be trained by means of inherent feed forward through interactive materiality. We address this approach in the context of designing an interactive toothbrush that supports users in learning a complex brushing technique by relying solely on their perceptual motor skills. We discuss how we designed a natural coupling according to the Frogger framework in the action-perception loops with the interactive toothbrush. We evaluated the toothbrush in context. The experimental results indicate that complex movements can be learned by providing inherent feed forward on the actions of users in skill training. This supports our argument and vision that the design-inspired approach or interactive materiality may offer new opportunities for behavioral transformation.

Control errors often occur in repetitive and monotonous tasks, such as manual assembly tasks. Much research has been done in the area of human error identification; however, most existing systems focus solely on the prediction of errors, not on increasing worker accuracy. The current study examines force responses before, during and after errors in a simulated assembly line task in order to determine an optimal feedback system for error reduction. Confirming previous findings, enhanced movement speed and reduced force occurred before erroneous trials and slowing occurred after erroneous trials. Given the results, we suggest a haptic feedback system which stimulates users to exert increased force levels after completing an erroneous task in order to increase degree of control and re-build worker confidence and thereby reduce overall error rate.

Sometimes, the way in which we interact with products implicitly communicates how we feel. Based on previous studies on how emotions can be detected and communicated via product interaction, we discuss how an interactive product could influence affect by responding and changing behaviors expressing affect. We discuss the proposal of the affective feedback loop in product interaction by its implementation in the prototype of a pen that senses two implicit behaviors related to restlessness, rock and roll. Furthermore, the pen provides inherent feedback, focusing on the perceptual motor skills, as a means to reflect on these behaviors. The pen was evaluated in an experiment, by which we explored whether this type of feedback would influence the emotional experience. Two participant groups were compared, and participants that used the pen with feedback showed a lower heart rate throughout the whole experiment. Because these participants were not aware that the pen provided any feedback, we propose the concept of unaware interaction and discuss what its implications are for design.

Affective computing focuses on the interpretation of users emotions via physiological and behavioral inputs. Irrelevant gestures with a pen were found to increase when users were given a mentally demanding task. Accordingly, an embedded tangible interface was developed which afforded and measured a rolling behavior, and guided the user towards reaching a balanced state of movement. During informal evaluations users acknowledged how the device could contribute to stress reduction. Conclusion, tangible interfaces appear to offer a non-obtrusive means towards interpreting and reducing stress in the office work context.