ReflecTrace: Touchless Hover Interaction on Commodity Smartphones via Corneal ReflectionWe propose an approach to detect finger hover inputs on a smartphone screen using corneal reflection images captured by the device’s built-in front camera. This method requires no external sensors or hardware, enabling hover input detection in the near-screen space that is not directly visible to the camera. By leveraging a convolutional neural network (CNN), we estimate the two-dimensional position of a hovering finger and classify it into a predefined screen grid. Experimental results show that our model achieves approximately 95% accuracy for coarse grids and maintains over 88% accuracy for finer divisions. Furthermore, our system demonstrates real-time processing capability with an end-to-end latency of approximately 22 ms on a standard smartphone. These findings highlight the practical feasibility of camera-only hover sensing and suggest a wide range of touchless interaction applications, enabling touchless interaction when touch is undesirable, pre-touch UI adaptation, and accessibility support on commodity mobile devices.2026YNYudai Nakamura et al.Keio UniversityMulti-Touch Interaction TechniquesMobile App User ExperienceMobile Accessibility DesignIUI
Y-zipper: 3D Printing Flexible–Rigid Transition Mechanism for Rapid and Reversible AssemblyWe present Y-zipper, a novel three-sided 3D-printed zipper structure that enables three flexible strips to interlock and transform into a rigid rod-like form. Building on this flex–rigid transition mechanism, we further design a specialized slider to achieve rapid and reversible zipping interactions. This slider serves as the basis for three actuation methods—manual, dynamic mechanical, and static mechanical—which enable both remote control and automated closure and release. In addition, Y-zipper provides four motion primitives: straight, bend, coil, and screw, whose combinations extend the flex–rigid transition mechanism to spatial curve structures. To support customization, we develop a computational design tool that automatically generates zipper geometry based on input primitives, unfolds the structure for 3D printing, and embeds both teeth and compliant bridges. Controlled experiments evaluate its mechanical properties, repeatability, and actuation speed, demonstrating robustness and reliability. Finally, we showcase a series of functional prototypes, including a medical wrist brace, a kinetic art installation, and a rapidly deployable tent structure.2026JLJiaji Li et al.MITShape-Changing Interfaces & Soft Robotic MaterialsCircuit Making & Hardware PrototypingCustomizable & Personalized ObjectsCHI
Zip-up Print: Rapid and Assemblable 3D printing Using 2D Flattened Zipper-like StructuresWe propose a method to fabricate objects composed of 3D printed flattened pieces with integrated zipper-like structures. The object is manually assembled into a 3D shape by connecting the zipper components. By employing a zipper design that allows for angle-independent connections between patches, our method enables both the surface and zipper components to be printed in the same orientation, resulting in high-quality reconstruction of the input model with a faster 3D printing process that wastes less material. We implement a fully automated pipeline that takes a 3D model as input, converts it into developable patches, generates the zipper structures, and flattens them for subsequent 3D printing. We demonstrate that our approach significantly reduces the fabrication time and support material consumption. We also present application examples that highlight the versatility of our method.2026TYTakumi Yamamoto et al.Keio UniversityDesktop 3D Printing & Personal FabricationShape-Changing Materials & 4D PrintingCHI
Sensing Your Vocals: Exploring the Activity of Vocal Cord Muscles for Pitch Assessment Using Electromyography and UltrasonographyVocal training is difficult because the muscles that control pitch, resonance, and phonation are internal and invisible to learners. This paper investigates how Electromyography (EMG) and ultrasonic imaging (UI) can make these muscles observable for training purposes. We report three studies. First, we analyze the EMG and UI data from 16 singers (beginners, experienced \& professionals), revealing differences among three vocal groups of the muscle control proficiency. Second, we use the collected data to create a system that visualizes an expert's muscle activity as reference. This system is tested in a user study with 12 novices, showing that EMG highlighted muscle activation nuances, while UI provided insights into vocal cord length and dynamics. Third, to compare our approach to traditional methods (audio analysis and coach instructions), we conducted a focus group study with 15 experienced singers. Our results suggest that EMG is promising for improving vocal skill development and enhancing feedback systems. We conclude the paper with a detailed comparison of the analyzed modalities (EMG, UI and traditional methods), resulting in recommendations to improve vocal muscle training systems.2026KCKanyu Chen et al.Graduate School of Media DesignBiosensors & Physiological MonitoringEmotion Recognition & DetectionAffective Feedback & Emotion Regulation InterfacesCHI
Peeking Ahead of the Field Study: Exploring VLM Personas as Support Tools for Embodied Studies in HCIField studies are irreplaceable but costly, time-consuming, and error-prone, which need careful preparation. Inspired by rapid-prototyping in manufacturing, we propose a fast, low-cost evaluation method using Vision-Language Model (VLM) personas to simulate outcomes comparable to field results. While LLMs show human-like reasoning and language capabilities, autonomous vehicle (AV)-pedestrian interaction requires spatial awareness, emotional empathy, and behavioral generation. This raises our research question: To what extent can VLM personas mimic human responses in field studies? We conducted parallel studies: 1) one real-world study with 20 participants, and 2) one video-study using 20 VLM personas, both on a street-crossing task. We compared their responses and interviewed five HCI researchers on potential applications. Results show that VLM personas mimic human response patterns (e.g., average crossing times of 5.25 s vs. 5.07 s) lack the behavioral variability and depth. They show promise for formative studies, field study preparation, and human data augmentation.2026XGXinyue Gui et al.The University of TokyoAutomated Driving Interface & Takeover DesignExternal HMI (eHMI) — Communication with Pedestrians & CyclistsUser Research Methods (Interviews, Surveys, Observation)CHI
Animacy and the Eye of the Beholder: A Mixed-Methods Study on Cognitive Animacy with a Kinetic Origami SurfacePrevious research shows how animacy attribution is shaped by perceptual and cognitive processes based on morphological and behavioural characteristics. Existing evidence is largely focused on passive observation of movement on a screen or scenarios involving predefined interactions. We explore cognitive animacy perceptions of 19 participants during embodied engagement with a spatial-scale kinetic origami surface with no defined interaction modalities. In a mixed-methods study, we collected EEG data, Godspeed Questionnaire evaluations, videos of participants engaging with the surface and semi-structured interviews to understand participants’ experiences. Our results show individuals' animacy perceptions are constructed through complex embodied meaning-making processes, affected by artifacts’ morpho-behavioural traits as well as individuals’ actions and interpretations. However, widespread brain activations make it hard to pinpoint to specific neurological phenomena. We unpack intrinsic and extrinsic factors shaping animacy perception, articulate the importance of ambiguity in the design of animate objects and present application scenarios for our prototype.2026CKCharalampos Krekoukiotis et al.Keio UniversityShape-Changing Interfaces & Soft Robotic MaterialsTangible User Interface DesignPhysical-Digital Hybrid InteractionCHI
Balancing Accuracy and Embodiment: A Hybrid Perspective for Complex Visuomotor Tasks in VRVisual perspective is a crucial design factor in Virtual Reality (VR). Especially when complex motor tasks are involved, it can affect both objective performance and subjective experience. We compared four visual perspectives (First-Person view, translucent Ghost view, Third-Person view, and Hybrid view) in a user study (N=20) involving different difficulties in a balancing game. Our findings reveal complex tradeoffs between the sense of embodiment, performance, and preference: The preferred Hybrid perspective offered a significant stability advantage for low task difficulty. However, this benefit vanished with increasing physical demand, revealing a speed-accuracy trade-off where external views required longer completion times. Ego-centric perspectives (First and Ghost) induced a stronger sense of embodiment and presence, but were less preferred. Participants' choice was not determined by representational fidelity but by pragmatic considerations of perceived utility. As perceived effectiveness can overrule objective performance and subjective experience, the choice of perspective is an important factor for future training and rehabilitation applications in VR.2026DDDennis Dietz et al.LMU MunichSocial & Collaborative VRImmersion & Presence ResearchVR Medical Training & RehabilitationCHI
Tell Me What I Missed: Interacting with GPT during Recalling of One-Time Witnessed EventsLLM-assisted technologies are increasingly used to support cognitive processing and information interpretation, yet their role in aiding memory recall—and how people choose to engage with them—remains underexplored. We studied participants who watched a short robbery video (approximating a one-time eyewitness scenario) and composed recall statements using either a default GPT or a guided GPT prompted with a standardized eyewitness protocol. Results show that default-condition participants who believed they had a clearer understanding of the event were more likely to trust GPT’s output, whereas guided-condition participants showed stronger alignment between subjective clarity and actual recall. Additionally, participants evaluated the legitimacy of the individuals in the incident differently across conditions. Interaction analysis further revealed that default-GPT users spontaneously developed diverse strategies, including building on existing recollections, requesting potentially missing details, and treating GPT as a recall coach. This work shows how GPT–user interplay subconsciously affects beliefs and perceptions of remembered events.2026SZSuifang Zhou et al.City University of Hong KongHuman-LLM CollaborationExplainable AI (XAI)Empathy & Emotional DesignCHI
Introspectus AI: Long-term AI-Driven Dialogue Training To Promote Self-ReflectionIntrospectusAI is a generative AI-based system designed to enhance self-reflection and support positive behavior change. By leveraging multimodal information from users' daily life recordings, it provides personalized and detailed feedback, aiming to deepen self-awareness and facilitate positive behavioral adjustments. This study explores the short-term and long-term impacts of interacting with IntrospectusAI, focusing on its potential to enhance reflective practices and improve the acceptance of generative AI tools. Following the user experience was defined through an initial round of workshops with four experts. The resulting system was evaluated through a long-term study involving 64 participants. The results demonstrate that AI-supported interventions significantly improved engagement in self-reflection, the need for reflection, and insight, while also increasing user acceptance of generative AI over time. These findings underscore the potential of generative AI as a practical tool for self-improvement, offering insights into its broader applicability in promoting well-being and personal growth.2025SLShengyin Li et al.Communicating With/Through AICSCW
SoilSense: Appropriating Soil-based Microbial Fuel Cells to Create Tangible InterfacesSoil-based Microbial Fuel Cells (SMFCs) offer a sustainable method for powering low-energy computing devices by harnessing electricity from microbial activity in soil. In this paper, we introduce SoilSense, a novel approach that repurposes SMFCs as tangible interfaces, transforming soil into an interactive, computationally responsive medium, instead of energy sources. We explore the voltage variations that occur when pressure is applied to the cathode and systematically characterize this mechanism across different electrode configurations and soil moisture levels. To demonstrate the feasibility of SMFC-based interfaces, we present a series of modular and proof-of-concept prototypes that support diverse interaction modalities. We further illustrate how SoilSense enables interactions through example applications and provide implications and envision for future studies to employ soil as an ecologically compatible material in interactive system design.2025TMTian Min et al.Shape-Changing Materials & 4D PrintingEcological Design & Green ComputingEnergy Conservation Behavior & InterfacesUIST
ScanRing: Hybrid Authentication System in a Ring Device Using a Distance Sensor and an IMU SensorSmart rings are used for contactless payment, smart lock operation, and health monitoring. For applications such as electronic payment and unlocking smart locks, the implementation of a user authentication system in smart rings is essential; however, some challenges remain. Fingerprint authentication is sensitive to fingertip conditions, while face authentication faces difficulties with miniaturization, power efficiency, and privacy. This study proposes ScanRing, a hybrid authentication system using a distance sensor and an IMU sensor in a smart ring. By moving the ring device laterally in front of the face, the distance sensor captures facial structure data, while the IMU sensor records the user’s motion characteristics. These combined datasets enable robust user authentication without relying on cameras, which enhances privacy while supporting a compact and power-efficient design. A user study (N = 30) demonstrated that ScanRing achieved an average authentication accuracy of 98.41 % under stable conditions.2025KMKai Miyashita et al.Passwords & AuthenticationMobileHCI
The Grounded Experience: The Effect of Floor Design Typologies on Human Behavioral and Cognitive ExperienceDesign reflects the human tendency to adapt to and inhabit surroundings, with architectural decisions significantly shaping behavioral and cognitive experiences. This pictorial focuses on the floor as a primary, embodied interface in space. To explore its influence, five floor design typologies (completing, switching, zoning, stimulating, and bending) were identified through twenty hours of expert discussions involving architects, designers, an artist, an engineer, and researchers. A collaborative workshop further defined sub-categories via participatory observations. Fieldwork then informed site selection for an observational study, which confirmed the behavioral and cognitive impacts of the identified typologies. Based on these findings, floor codes were developed by shifting the design focus from visual cues to somatic sensations and applied in design scenarios. This research contributes to understanding human experience in architectural environments. It offers insights for virtual architecture, proposing evidence-based strategies for designing personalized and interactive spaces in virtual and mixed-reality contexts.2025BDBurcu Nimet Dumlu et al.Mixed Reality WorkspacesDigital Art Installations & Interactive PerformanceInteractive Narrative & Immersive StorytellingDIS
Crafting the Unspoken: Engaging Japanese Older Adults with Data Physicalization WorkshopsEngaging individuals in creating physical representations of personal data facilitates storytelling and collaborative reflection. However, its potential to encourage older adults to share their personal stories remains underexplored. This study introduces a craft-centered data physicalization approach where participants create tangible representations of their emotions and experiences related to community events, involving both event attendees and event organizers, through a series of workshops. This collaborative crafting process encourage group discussions and collective reflections on past experiences, enabling participants to express thoughts and feelings that would otherwise remain unspoken. Our work contributes a practical workshop approach that merges craft practice with data physicalization to support deep social expressions and connections among older adults.2025CLChengtian Li et al.Data PhysicalizationMakerspace CultureEmpowerment of Marginalized GroupsDIS
"If I were in Space": Understanding and Adapting to Social Isolation through Designing Collaborative StorytellingSocial isolation can lead to pervasive health issues like anxiety and loneliness. Previous work focused on physical interventions like exercise and teleconferencing, but overlooked the narrative potential of adaptive strategies. To address this, we designed a collaborative online storytelling experience in social VR, enabling participants in isolation to design an imaginary space journey as a metaphor for quarantine, in order to learn about their isolation adaptation strategies in the process. Eighteen individuals participated during real quarantine undertaken a virtual role-play experience, designing their own spaceship rooms and engaging in collaborative activities that revealed creative adaptative strategies. Qualitative analyses of participant designs, transcripts, and interactions revealed how they coped with isolation, and how the engagement unexpectedly influenced their adaptation process. This study shows how designing playful narrative experiences, rather than solution-driven approaches, can serve as probes to surface how people navigate social isolation.2025QGQi Gong et al.Social & Collaborative VRIdentity & Avatars in XRSTEM Education & Science CommunicationDIS
MaGEL: A Soft, Transparent Input Device Enabling Deformation Gesture RecognitionWe propose MaGEL, a soft-input device that utilizes light intensity to detect and interpret user deformation interactions. Unlike traditional rigid input devices, MaGEL enables three-dimensional interactions such as twisting, bending, and pulling. Additionally, MaGEL incorporates elastic haptic feedback, providing users with tactile sensations that reflect the tension or resistance of their interactions. These factors realize intuitive and natural user interaction experiences, and users can employ familiar physical gestures as input. For example, bending the device may simulate turning the page of a book, or stretching it may zoom in on an image. The device consists of a transparent urethane resin gel with LED lights and phototransistors on both sides. When the device gel deforms, the intensity of the light passing through the gel undergoes a specific change due to the deformation. The system analyzes these changes using machine learning to identify the user gestures. We evaluated the optimal configuration and number of LEDs and phototransistors to classify the deformation accurately. We acquired data for 13 types of deformation gestures from 14 participants. The results showed that a combination of four LEDs and ten phototransistors enabled MaGEL to identify 13 types of deformation gestures with an accuracy of 94.1 %. Using MaGEL, we provide novel interactive experiences, such as game controllers that employ bending, pulling, or twisting to mimic natural gaming motions.2025FOFumika Oguri et al.Shape-Changing Interfaces & Soft Robotic MaterialsHand Gesture RecognitionIUI
A Reflective Journey for Individuals with Intellectual Disabilities: Rediscovering Competency Through AI-Enhanced Iron Beads CraftingIn addition to trained work skills, employed individuals with intellectual disabilities (IDs) possess unique competencies that are often insufficiently supported or overlooked by both themselves and their work environments. This study proposes using reflective practices to help employees with IDs and employers rediscover competencies beyond job-related skills. To facilitate participation, we employed personalized crafting with iron beads, supported by a custom-developed application integrated with text-to-image generative AI. We conducted two workshops involving 5–7 employees with IDs to explore and enhance our approach to competency discovery. In the first workshop, facilitators manually created templates for participants, while in the second, we leveraged an AI-assisted application for self-creation of personalized templates. Findings from group discussions reveal (1) the development of a framework that positions AI-enhanced crafting activities as an effective way for uncovering and fostering competencies, and (2) insights into reflection on self-concept as a foundation for competency development.2025SCsifan chen et al.Keio University Graduate School of Media DesignGenerative AI (Text, Image, Music, Video)Special Education TechnologyCHI
A Placebo Concert: The Placebo Effect for Visualization of Physiological Audience Data during Experience Recreation in Virtual RealityA core use case for Virtual Reality applications is recreating real-life scenarios for training or entertainment. Promoting physiological responses for users in VR that match those of real-life spectators can maximize engagement and contribute to more co-presence. Current research focuses on visualizations and measurements of physiological data to ensure experience accuracy. However, placebo effects are known to influence performance and self-perception in HCI studies, creating a need to investigate the effect of visualizing different types of data (real, unmatched, and fake) on user perception during event recreation in VR. We investigate these conditions through a balanced between-groups study (n=44) of uninformed and informed participants. The informed group was provided with the information that the data visualizations represented previously recorded human physiological data. Our findings reveal a placebo effect, where the informed group demonstrated enhanced engagement and co-presence. Additionally, the fake data condition in the informed group evoked a positive emotional response.2025XMXiaru Meng et al.Keio University Graduate School of Media DesignSocial & Collaborative VRImmersion & Presence ResearchVisualization Perception & CognitionCHI
A Critical Review of Sexuality, Technology and DisabilityThe investigation of technologies facilitating sexual interactions and sexuality-related explorations is becoming more established in Human-Computer Interaction (HCI), albeit with little systematic attention to the sexual lives of disabled people. In this space, we undertook a literature review utilising feminist content analysis to take stock and critically analyse the domains of sexuality, technology and disability when they intersect. Our approach aligns with the broader goals of promoting inclusivity, diversity, and equity in technology design and application. We present a descriptive and analytical outline of existing research on sexuality, technology and disability through which we identified unmarked norms governing research. These include a focus on individualised technologies oriented on heteronormative assumptions on sexual desires. In addition, we focus on common methods employed and describe the involvement, or lack thereof, of disabled people in research practice. This highlights gaps in our collective knowledge from which we can derive areas for future work2025DPDilisha Patel et al.UCL, Global Disability Innovation HubCognitive Impairment & Neurodiversity (Autism, ADHD, Dyslexia)Gender & Race Issues in HCIEmpowerment of Marginalized GroupsCHI
Sticking With Electronics for Crafting Practices: An Inclusive Approach to Promote Making Literacy Among Older AdultsMaking activities have been shown to offer potential for inclusive access to digital literacy amongst marginalized groups, but research exploring such approaches with older adults is still scarce. Our study introduces an electronic-card-making workshop, co-developed with Japanese older women to foster engagement aligning with their purpose, physical and cognitive skills. The workshop was initially delivered to 14 women. Following initial success, 4 participants decided to deliver a second workshop, with the support of our team, for 15 local children. We present findings from both these workshops unpacking how women's motivation for engaging in eMaking revolved around the idea of sharing, both through displaying created artefacts and the transmission of knowledge, how their learning consolidated around implicit actions and was supported by the creation of escalation strategies when they felt that demands exceeded their level of proficiency. Based on our results, we propose guidelines for inclusive eMaking involving novice older women.2025GBGiulia Barbareschi et al.Keio University, Keio Graduate School of Media DesignHaptic WearablesAging-Friendly Technology DesignMakerspace CultureCHI
The Role of ICT Tools through a Community Program Co-creation in a Japanese Aging CommunityAs the global aging population grows and technology advances rapidly, integrating technology into community-based initiatives for older adults has become an increasingly important topic among HCI researchers. This research explores the role of Information and Communication Technology (ICT) tools in the co-creation and maintenance of a community gardening program involving researchers, older adult residents, and supporting organizations. A follow-up study, conducted eight months after the program’s initiation assessed its sustainability, revealing how stakeholders navigated diverse ICT preferences and challenges by employing a hybrid communication system that integrated both digital and face-to-face methods to foster collaboration and sustain the initiative. This research contributes to the understanding of community preferences and needs, and the importance of contextualizing technology use within Japanese local community for collaborative community development.2025JZJianrui Zhao et al.Keio University, Graduate School of Media DesignAging-in-Place Assistance SystemsCommunity Engagement & Civic TechnologyCHI