Surfing, like many water sports, offers a unique opportunity to experience natural environments, yet the design of interactive technologies for water activities– “WaterHCI” – so far prioritised athletic performance over experience. To explore this opportunity, we designed SurfSync, a novel wearable system in the form of an actuating vest and a hat that provides oceanic information through sound, vibration, and heat actuation, aimed at enriching the surfing experience as a playful encounter with the ocean. We studied SurfSync in an ocean-based field study with eight surfers. Through thematic analysis of interviews, we articulated the surfers’ experiences, indicating how they made sense of playful cues while in the ocean. By reflecting on our soma design process and the surfers’ experiences, we provide six design strategies to enrich the surfing experience. Our work contributes to the emerging field of WaterHCI by providing insights into how wearables can enrich human-water experiences outdoors.

Advances in emerging technologies, such as on-body mechanical actuators and electrical muscle stimulation, have allowed computers to take control over our bodies. This presents opportunities as well as challenges, raising fundamental questions about agency and the role of our bodies when interacting with technology. To advance this research field as a whole, we brought together expert perspectives in a week-long seminar to articulate the grand challenges that should be tackled when it comes to the design of computers’ control over our bodies. These grand challenges span technical, design, user, and ethical aspects. By articulating these grand challenges, we aim to begin initiating a research agenda that positions bodily control not only as a technical feature but as a central, experiential, and ethical concern for future human–computer interaction endeavors.

• Presents a two-dimensional design space around body schema and body image for playful bodily extensions. • Details designers’ experiences creating playful bodily extensions. • Articulates practical strategies for the design of future playful bodily extensions. Interaction designers are increasingly interested in physically extending people's bodies and emerging work shows the potential of such bodily extensions for play, one example being interactive fantasy ears for the Cosplay community. We interviewed five designers of four playful bodily extensions to better understand how to design them. Based on their insights and our examination of prior work, we argue that such extensions can be characterized by the extent to which they alter the wearer's body schema and body image. We illustrate this characterization using a two-dimensional design space. We use this design space to articulate practical strategies for the design of future playful bodily extensions. Ultimately, we hope to bring more playful experiences to people's lives.

Traditional games like "Tag" rely on shared control via inter-body interactions (IBIs) – touching, pushing, and pulling – that foster emotional and social connection. Digital games largely limit IBIs, with players using their bodies as input to control virtual avatars instead. Our “Shared Bodily Fusion” approach addresses this by fusing players’ bodies through a mediating computer, creating a shared input and output system. We demonstrate this approach with "Hidden Touch", a game where a novel social electrical muscle stimulation system transforms touch (input) into muscle actuations (output), facilitating IBIs. Through a study (n=27), we identified three player experience themes. Informed by these findings and our design process, we mapped their trajectories across our three experiential spaces – threshold, tolerance, and precision – which collectively form our design framework. This framework facilitates the creation of future digital games where IBIs are intrinsic, ultimately promoting the many benefits of social play.

Underlying humanity’s social abilities is the brain’s capacity to interpersonally synchronize. Experimental, lab-based neuropsychological studies have demonstrated that inter-brain synchrony can be technologically mediated. However, knowledge in deploying these technologies in-the-wild and studying their user experience, an area HCI excels in, is lacking. With advances in mobile brain sensing and stimulation, we identify an opportunity for HCI to investigate the in-the-wild augmentation of inter-brain synchrony. We designed “PsiNet,” the first wearable brain-to-brain system aimed at augmenting inter-brain synchrony in-the-wild. Participant interviews illustrated three themes that describe the user experience of modulated inter-brain synchrony: hyper-awareness; relational interaction; and the dissolution of self. We contribute these three themes to assist HCI theorists’ discussions of inter-brain synchrony experiences. We also present three practical design tactics for HCI practitioners designing inter-brain synchrony, and hope that our work guides a HCI future of brain-to-brain experiences which fosters human connection.

Prior research around the design of interactive systems has highlighted the benefits of supporting embodiment in everyday life. This resulted in the creation of body-centric systems that leverage movement. However, these advances supporting movement in everyday life, aligning with the embodiment theory, so far focused on sensing movement as opposed to facilitating movement. We present PneuMa, a novel wearable system that can facilitate movement in everyday life through pneumatic-based bodily extensions. We showcase the system through three examples: "Pardon?", moving the ear forward; "Greetings", moving a hand towards the "Bye-bye" gesture; "Take a break", moving the hands away from the keyboard, enabling the bodily extensions that support movement in everyday life. From the thematic analysis of a field study with 12 participants, we identified three themes: bodily awareness, Perception of the scenarios, and anticipating movement. We discuss our findings in relation to prior research around bodily extensions and embodied interaction to provide strategies to design bodily extensions that support movement in everyday life. Ultimately, we hope that our work helps more people profit from the benefits of everyday movement support.

Contemporary human-food interaction design is often a technology-driven endeavor in which food's materiality has been largely underexplored. Building on the concept of “computational food”, this paper explores the design of food as a material realization of computation through a material-centered approach. We engaged with a “Research through Design” exploration by designing a computational food system called “Dancing Delicacies”, which enables food items to be “programmed” and “reconfigured” within dynamic trajectories. Our practice led to a design framework resulting in four original dish designs. Our dishes aim to illustrate the richness of this new design space for computational food. Furthermore, through engaging with expert practitioners from the hospitality industry, we provide a first account of understanding the design of computational food for dynamic dining trajectories and its speculative use contexts in the industry. With this work, we hope to inspire researchers and designers to envision a new future of human-food interaction.

Our bodies play an important part in our remembering practices, for example when we can remember passwords by typing, even if we cannot verbalise them. An increasing number of technologies are being developed to support remembering. However, so far, they seem to have not taken the opportunity yet to support remembering through bodily movements. To better understand how to design for such embodied remembering, we conducted a diary study with 12 participants who recorded their embodied remembering experiences in everyday life over a three-week period. Our thematic analysis of the diaries and interviews led to the creation of a framework that helps understand embodied remembering experiences (ERXs) based on the level of skilled and conscious movements used. We describe how this ERX framework could help with the design of technologies to support embodied remembering.

Water's pleasant nature and associated health benefits have captivated the interest of HCI researchers. Prior WaterHCI work mainly focused on advancing instrumental applications, such as improving swimming performance, and less on designing systems that support interacting with technology in water in more playful contexts. In this regard, we propose floatation tanks as research vehicles to investigate the design of playful interactive water experiences. Employing somaesthetic design, we developed a playful extended reality floatation tank experience: "Fluito". We conducted a 13-participant study to understand how specific design features amplified participants' water experiences. We used a postphenomenological lens to articulate eight strategies useful for designers aiming to develop digital playful experiences in water, such as designing to call attention to the water and designing to encourage breathing and body awareness in water experiences. Ultimately, we hope that our work supports people to be playful and benefit from the many advantages of being in water.

Most digital bodily games focus on the body as they use movement as input. However, they also draw the player’s focus away from the body as the output occurs on visual displays, creating a divide between the physical body and the virtual world. We propose a novel approach – the "Body as a Play Material" – where a player uses their body as both input and output to unify the physical body and the virtual world. To showcase this approach, we designed three games where a player uses one of their hands (input) to play against the other hand (output) by loaning control over its movements to an Electrical Muscle Stimulation (EMS) system. We conducted a thematic analysis on the data obtained from a field study with 12 participants to articulate four player experience themes. We discuss our results about how participants appreciated the engagement with the variety of bodily movements for play and the ambiguity of using their body as a play material. Ultimately, our work aims to unify the physical body and the virtual world.

Spectating digital games can be exciting. However, due to its vicarious nature, spectators often wish to engage in the gameplay beyond just watching and cheering. To blur the boundaries between spectators and players, we propose a novel approach called "Fused Spectatorship", where spectators watch their hands play games by loaning bodily control to a computational Electrical Muscle Stimulation (EMS) system. To showcase this concept, we designed three games where spectators loan control over both their hands to the EMS system and watch them play these competitive and collaborative games. A study with 12 participants suggested that participants could not distinguish if they were watching their hands play, or if they were playing the games themselves. We used our results to articulate four spectator experience themes and four fused spectator types, the behaviours they elicited and offer one design consideration to support each of these behaviours. We also discuss the ethical design considerations of our approach to help game designers create future fused spectatorship experiences.

Jewelry weaves into our everyday lives as no other wearable does. It comes in many wearable forms, is fashionable, and can adorn any part of the body. In this paper, through an exploratory, Research through Design (RtD) process, we tap into this vast potential space of input interaction that jewelry can enable. We do so by first identifying a small set of fundamental structural elements --- called Jewelements --- that any jewelry is composed of, and then defining their properties that enable the interaction. We leverage this synthesis along with observational data and literature to formulate a design space of jewelry-enabled input techniques. This work encapsulates both the extensions of common existing input methods (e.g., touch) as well as new ones inspired by jewelry. Furthermore, we discuss our prototypical sensor-based implementations. Through this work, we invite the community to engage in the conversation on how jewelry as a material can help shape wearable-based input.

Often Virtual Reality (VR) experiences are limited by the design of standard controllers. This work aims to liberate a VR developer from these limitations in the physical realm to provide an expressive match to the limitless possibilities in the virtual realm. VirtualBricks is a LEGO based toolkit that enables construction of a variety of physical-manipulation enabled controllers for VR, by offering a set of feature bricks that emulate as well as extend the capabilities of default controllers. Based on the LEGO platform, the toolkit provides a modular, scalable solution for enabling passive haptics in VR. We demonstrate the versatility of our designs through a rich set of applications including re-implementations of artifacts from recent research. We share a VR Integration package for integration with Unity VR IDE, the CAD models for the feature bricks, for easy deployment of VirtualBricks within the community.