The sound produced when touching fabrics, like a blanket, often provides information regarding the fabric’s texture properties (e.g., its roughness). Fabric roughness is one of the most important aspects of assessing fabric tactile properties. Prior research has demonstrated that touch-related sounds can alter the perception of textures. However, understanding touch-related sound of digital fabric textures, and how they could convey affective responses remain a challenge. In this study, we mapped digital fabric textures using mid-air haptics stimuli and examined how auditory manipulation influences people’s roughness perception. Through qualitative interviews, participants detailed that while rubbing sounds smoothen fabric texture perception, pure tone sounds of 450Hz and 900Hz accent roughness perception. The rubbing sound of fabric evoked associations with soft-materials and led to more calming experiences. In addition, we discussed how haptic interaction can be extended to multisensory modes, revealing a new perspective of mapping multisensory experiences for digital fabrics.

Human perception of touch is a complex interplay of sensory inputs, extending beyond tactile stimuli to include visual and auditory cues. Yet, the potential of olfactory cues (e.g., scents) to enrich our understanding and experiences of digital touch remains largely unexplored. This paper explores the integration of scent with digital haptic feedback, specifically focusing on the perception of textiles using an ultrasonic mid-air haptic device. In an initial validation study, we identified scents associated with the tactile properties of roughness, smoothness, coldness, and warmth based on participant ratings (n = 31). In a subsequent immersive Virtual Reality (VR) experiment, we explored how these scents might affect perceptions of digital textiles presented using ultrasonic mid-air haptics (n = 32). Our results suggested that while scents did not affect the tactile properties of digital textiles, participants reported the sensations feeling more realistic and more arousing according to the scent delivered. This multimodal integration of scent with digital haptic stimuli can open up the creation of more immersive experiences and more in-depth understanding of digital material properties.

The rapid development of touchless systems has introduced many innovations in social interaction scenarios in recent years. People now can interact with touchless systems in social applications that are aimed to be used in everyday situations in the future. This accelerated development makes us ask, what will the next generation of touchless systems be like? How can we responsibly develop new touchless technologies in the future? To answer the first question, we brought together 20 experts to ideate, speculate, and evaluate possible touchless applications for social interactions. A total of 48 ideas were generated from two consecutive workshops. Then, to answer the second question, we critically analyzed those ideas through a thematic analysis using a responsible innovation (RI) framework, and identified key ethical considerations to guide developers, practitioners when designing future touchless systems. We argue that the social scenarios described, and the RI framework proposed in this paper are a useful starting point for responsibly designing the next generation of touchless systems.

Previous research has shown the influence of smell on emotions, memories, and body image. However, most of this work has taken place in laboratory settings and little is known about the influence of smell in real-world environments. In this article, we present novel insights gained from a field study investigating the emotional effect of smell on memories and body image. Taking inspiration from the cultural design probes approach, we designed QuintEssence, a probe package that includes three scents and materials to complete three tasks over a period of four weeks. Here, we describe the design of QuintEssence and the main findings based on the outcomes of the three tasks and a final individual interview. The findings show similar results between participants based on the scent. For example, with cinnamon, participants experienced feelings of warmth, coziness, happiness, and relaxation; they recalled blurred memories of past moments about themselves and reported a general feeling of being calm and peaceful towards their bodies. Our findings open up new design spaces for multisensory experiences and inspire future qualitative explorations beyond laboratory boundaries.

The Sense of Agency (SoA) is crucial in interaction with technology, it refers to the feeling of 'I did that' as opposed to 'the system did that' supporting a feeling of being in control. Research in human-computer interaction has recently studied agency in visual, auditory and haptic interfaces, however the role of smell on agency remains unknown. Our sense of smell is quite powerful to elicit emotions, memories and awareness of the environment, which has been exploited to enhance user experiences (e.g., in VR and driving scenarios). In light of increased interest in designing multimodal interfaces including smell and its close link with emotions, we investigated, for the first time, the effect of smell-induced emotions on the SoA. We conducted a study using the Intentional Binding (IB) paradigm used to measure SoA while participants were exposed to three scents with different valence (pleasant, unpleasant, neutral). Our results show that participants? SoA increased with a pleasant scent compared to neutral and unpleasant scents. We discuss how our results can inform the design of multimodal and future olfactory interfaces.

Scale adaptive techniques for VR navigation enable users to navigate spaces larger than the real space available, while allowing precise interaction when required. However, due to these techniques gradually scaling displacements as the user moves (changing user's speed), they introduce a Drift effect. That is, a user returning to the same point in VR will not return to the same point in the real space. This mismatch between the real/virtual spaces can grow over time, and turn the techniques unusable (i.e., users cannot reach their target locations). In this paper, we characterise and analyse the effects of Drift, highlighting its potential detrimental effects. We then propose two techniques to correct Drift effects and use a data driven approach (using navigation data from real users with a specific scale adaptive technique) to tune them, compare their performance and chose an optimum correction technique and configuration. Our user study, applying our technique in a different environment and with two different scale adaptive navigation techniques, shows that our correction technique can significantly reduce Drift effects and extend the life-span of the navigation techniques (i.e., time that they can be used before Drift draws targets unreachable), while not hindering users' experience.

The Sense of Agency (SoA) refers to our capability to control our own actions and influence the world around us. Recent research in HCI has been investigating SoA to provide users an instinctive sense of "I did that" as opposed to "the system did that". However, current agency measurements are limited. The Intentional Binding (IB) paradigm provides an implicit measure of the SoA, however, it is constrained by requiring high visual attention to a "Libet clock" on-screen. In this paper, we extended the timing stimuli through auditory and tactile cues. Our results demonstrate that audio timing through voice commands and haptic timing through tactile cues on the hand, are an effective alternative measure of the SoA using the IB paradigm. They both address current limitations of the traditional method such as visual attention overload and lack of engagement. We discuss how our results can be applied to measure SoA in tasks involving different interactive scenarios such as in Mixed/Virtual Reality.

Touchless interfaces allow users to view, control and manipulate digital content without physically touching an interface. They are being explored in a wide range of application scenarios from medical surgery to car dashboard controllers. One aspect of touchless interaction that has not been explored to date is the Sense of Agency (SoA). The SoA refers to the subjective experience of voluntary control over actions in the external world. In this paper, we investigated the SoA in touchless systems using the intentional binding paradigm. We first compare touchless systems with physical interactions and then augmented different types of haptic feedback to explore how different outcome modalities influence intentional binding. From our experiments, we demonstrated that an intentional binding effect is observed in both physical and touchless interactions with no statistical difference. Additionally, we found that haptic and auditory feedback help to increase SoA compared with visual feedback in touchless interfaces. We discuss these findings and identify design opportunities that take agency into consideration.