Rijke Squeeze-interacties: Detectietechnieken en Toepassingen voor Emotieregulatie op de Werkplek

From a child gripping a parent's hand to an affectionate hug or the unconscious fidgeting with a stress ball, squeezing is a natural human action embedded in our daily lives. In Human-Computer Interaction (HCI), squeezable interfaces have found varied applications, spanning musical instruments, modelling tools, robotic skins, and affective interfaces. Importantly, squeezable interfaces, even without digital feedback, have shown promise in alleviating negative emotions. This PhD research has two primary focuses: first, developing accessible and reliable sensing solutions for squeezable interfaces; and second, exploring how these interfaces can support affective well-being, with particular attention to helping desk workers regulate their emotions in workplace settings. This dissertation begins with the exploration of accessible and reliable squeeze sensors based on conductive polyurethane (PU) foam. Various electrode materials and configurations were systematically investigated, with a particular focus on the static and dynamic electrical behaviours of sensors constructed using conductive threads. In contrast to conventional methods that aim to minimise contact resistance, this research discovered an approach that leverages contact resistance to significantly enhance sensing sensitivity. Beyond sensor development, this work also sought to understand how tangible, squeezable interfaces can support human affective needs—particularly emotion regulation (ER). To ground this investigation, a literature review was conducted of 50 papers on tangible user interfaces (TUIs) designed for affective interaction, synthesizing how tangibility can be leveraged to facilitate affective interactions. Recognising the limited focus on workplace settings within this body of literature, this PhD research subsequently investigated how established ER practices could be integrated into squeezable interfaces to support the emotional well-being of office workers. This phase of the investigation included interviews with five mental health experts and 16 desk workers, as well as five co-design workshops involving 17 desk workers. Through this process, key design opportunities were identified and specific considerations for developing tangible, embodied interactions tailored to the workplace context were outlined. Building on these foundational insights, a research product named BLOOM was designed, developed, and evaluated through a field study. BLOOM is a tangible interface for ER in office environments, aiming at investigate how TUIs with calming metaphors should be designed to support ER in public workplace settings. BLOOM combines a lotus flower with dynamic blooming movements and on-screen breathing guidance, alongside a squeezable pebble that encourages somatic engagement by synchronising muscle relaxation with breath. The system was deployed across three office buildings for 10 to 15 working days. Mixed-methods data were collected through 17 surveys and 10 interviews to assess the users' perceptions of the system's design, its emotional impact, and its influence on social dynamics in the office. While the nature-inspired aesthetic was well received, passive engagement led to limited calming effects, underscoring the importance of active, embodied interaction. Additionally, individual sensory preferences, workplace stigma, and the surrounding social context were found to significantly shape user experiences. Finally, the dissertation concludes with a reflection on the valorisation of its outcomes, followed by an overall conclusion that revisits the research questions, synthesises overarching themes, reflects on the study's limitations, and outlines directions for future research.