eTactileKit: A Toolkit for Design Exploration and Rapid Prototyping of Electro-Tactile InterfacesElectro-tactile interfaces are becoming increasingly popular due to their unique advantages, such as delivering fast and localised tactile response, thin and flexible form factors, and the potential to create novel tactile experiences. However, insights from a formative study with typical designers highlighted the lack of resources, limited access to information and complexity of software and hardware tools. This establishes a high barrier to entry and limits the ability to rapidly prototype and experiment with electro-tactile interfaces. To address these challenges, we propose eTactileKit, a scalable and accessible toolkit providing end-to-end support for designing and prototyping electro-tactile interfaces. eTactileKit comprises a hardware platform and a software framework for designing, simulating and exploring electro-tactile stimuli. We evaluated the impact and usability of eTactileKit through a three-week long take-home study, which demonstrated increased accessibility, ease of use, and the toolkit's positive impact on design workflow. Additionally, we implemented a set of use cases to demonstrate the toolkit's practicality and effectiveness across various applications.2025PPPraneeth Bimsara Perera et al.Electrical Muscle Stimulation (EMS)Prototyping & User TestingUIST
Buoyancé: Reeling Helium-Inflated Balloons with Mobile Robots on the Ground for Mid-Air Tangible Display, Interaction, and AssemblyWe introduce a novel approach to spatially actuated tangible UI by controlling helium-inflated balloons (HIBs) in mid-air using mobile reeling robots, named ReelBots. With a relatively compact device form factor, the robots can manipulate HIBs in an extensive vertical range, reaching relatively high altitudes (20m or more), thanks to its reeling mechanisms. The hardware offers diverse interactive functionalities and applications for representing abstract data in 3D space, reconfiguring lights and cameras in an everyday space, and assembling HIBs into diverse configurations. Our proof-of-concept implementation was developed based on omnidirectional mobile robots and a motion tracking system to demonstrate the novel approach of enriching 3D physical space. Our control software is designed to manipulate multiple robots to control the position of HIBs in real time via multiple options ranging from GUI control and tangible and gesture based controls.2025APAlan Pham et al.Shape-Changing Interfaces & Soft Robotic MaterialsDigital Art Installations & Interactive PerformanceUIST
Integrating Force Sensing with Electro-Tactile Feedback in 3D Printed Haptic InterfacesTactile feedback mechanisms enhance the user experience of modern wearables by stimulating the sense of touch and enabling intuitive interactions. Electro-tactile stimulation-based tactile interfaces stand out due to their compact form factor and ability to deliver localized tactile sensations. Integrating force sensing with electro-tactile stimulation creates more responsive bidirectional systems that are beneficial in applications requiring precise control and feedback. However, current research often relies on separate sensors for force sensing, increasing system complexity and raising challenges in system scalability. We propose a novel approach that utilizes 3D-printed modified surfaces as the electro-tactile electrode interface to sense applied force and deliver feedback simultaneously without additional sensors. This method simplifies the system, maintains flexibility, and leverages the rapid prototyping capabilities of 3D printing. The functionality of this approach is validated through a user study (N=10), and two practical applications are proposed, both incorporating simultaneous sensing and tactile feedback.2024PPPraneeth Bimsara Perera et al.Force Feedback & Pseudo-Haptic WeightElectrical Muscle Stimulation (EMS)Desktop 3D Printing & Personal FabricationUbiComp
ALCool: Utilizing Alcohol's Evaporative Cooling for Ubiquitous Cold Sensation FeedbackTactile technologies are important for novel user experiences. Among several tactile submodalities, cold sensation is essential for realistically portraying materials and environments. However, current cold presentations such as Peltier devices face challenges like low energy efficiency and the need for complicated equipment. To address these, we suggest leveraging alcohol's endothermic property during evaporation. Our prototype, a wristwatch wearable with a fan, capitalizes on alcohol's high volatility by absorbing ambient heat upon evaporation. The device further enhances the cooling effect by circulating air around the skin. This approach simplifies the setup required for cooling technologies and is more energy-efficient than Peltier-based systems. We also integrated perfume, which is a mixture of alcohol and scent substance, and presented a unique cooling and scent experience. The use of alcohol as a cooling method was not considered conventional, but social changes after COVID-19 made it easy to obtain a tiny amount of alcohol.2024THTakumi Hamazaki et al.The University of Electro-CommunicationsHaptic WearablesCHI
VabricBeads : Variable Stiffness Structured Fabric using Artificial Muscle in Woven BeadsWoven beads, a structured fabric category, comprises interconnected rows of beads joined by fiber strands. While the stiffness of woven beads can be adjusted by relying on fiber tension during fabrication, the resulting shape and stiffness properties remain fixed. This study explores the potential of tunable shape and stiffness in woven beads, offering adaptability in comfort, functionality, and form factor. By leveraging Pneumatic Artificial Muscles (PAMs), we employ a state-of-the-art technique for dynamically modulating fabric stiffness through mechanical constraints in bead form. This approach enables a modular and scalable fabrication process, fostering programmability in mechanical properties. Our investigation encompasses diverse bead iterations and stitching patterns to broaden their applicability in fabric behavior including degree of freedom, stretchability, permeability, and textures. We evaluate the mechanical properties to differentiate design capabilities, and present techniques for locally adjusting stiffness. We showcase the versatility through applications, including variable stiffness wearables and shape-changing everyday objects.2024JPJefferson Pardomuan et al.Tokyo Institute of TechnologyHaptic WearablesShape-Changing Interfaces & Soft Robotic MaterialsShape-Changing Materials & 4D PrintingCHI
"Off Script:" Design Opportunities Emerging from Long-Term Social Robot Interactions In-the-WildSocial robots are becoming increasingly prevalent in the real world. Unsupervised user interactions in a natural and familiar setting, such as the home, can reveal novel design insights and opportunities. This paper presents an analysis and key design insights from family-robot interactions, captured via on-robot recordings during an unsupervised four-week in-home deployment of an autonomous reading companion robot for children. We analyzed interviews and 160 interaction videos involving six families who regularly interacted with a robot for four weeks. Throughout these interactions, we observed how the robot's expressions facilitated unique interactions with the child, as well as how family members interacted with the robot. In conclusion, we discuss five design opportunities derived from our analysis of natural interactions in the wild.2023JMSaya Amioka et al.Smart Home Interaction DesignSocial Robot InteractionHRI
Limitations of Audiovisual Speech on Robots for Second Language Pronunciation LearningThe perception of audiovisual speech plays an important role in infants' first language acquisition and continues to be important for language understanding beyond infancy. Beyond that, the perception of speech and congruent lip motion supports language understanding for adults, and it has been suggested that second language learning benefits from audiovisual speech, as it helps learners distinguish speech sounds in the target language. In this paper, we study whether congruent audiovisual speech on a robot facilitates the learning of Japanese pronunciation. 27 native-Dutch speaking participants were trained in Japanese pronunciation by a social robot. The robot demonstrated 30 Japanese words of varying complexity using either congruent audiovisual speech, incongruent visual speech, or computer-generated audiovisual speech. Participants were asked to imitate the robot's pronunciation, recordings of which were rated by native Japanese speakers. Against expectation, the results showed that congruent audiovisual speech resulted in lower pronunciation performance than low-fidelity or incongruent speech. We show that our learners, being native Dutch speakers, are only very weakly sensitive to audiovisual Japanese speech which possibly explains why learning performance does not seem to benefit from audiovisual speech.2023SASaya Amioka et al.Force Feedback & Pseudo-Haptic WeightSocial Robot InteractionHRI
Increasing Electrical Muscle Stimulation’s Dexterity by means of Back of the Hand ActuationWe propose a technique that allows an unprecedented level of dexterity in electrical muscle stimulation (EMS), i.e., it allows interactive EMS-based devices to flex the user’s fingers independently of each other. EMS is a promising technique for force feedback because of its small form factor when compared to mechanical actuators. However, the current EMS approach to flexing the user’s fingers (i.e., attaching electrodes to the base of the forearm, where finger muscles anchor) is limited by its inability to flex a target finger’s metacarpophalangeal (MCP) joint independently of the other fingers. In other words, current EMS devices cannot flex one finger alone, they always induce unwanted actuation to adjacent fingers. To tackle the lack of dexterity, we propose and validate a new electrode layout that places the electrodes on the back of the hand, where they stimulate the interossei/lumbricals muscles in the palm, which have never received attention with regards to EMS. In our user study, we found that our technique offers four key benefits when compared to existing EMS electrode layouts: our technique (1) flexes all four fingers around the MCP joint more independently; (2) has less unwanted flexion of other joints (such as the proximal interphalangeal joint); (3) is more robust to wrist rotations; and (4) reduces calibration time. Therefore, our EMS technique enables applications for interactive EMS systems that require a level of flexion dexterity not available until now. We demonstrate the improved dexterity with four example applications: three musical instrumental tutorials (piano, drum, and guitar) and a VR application that renders force feedback in individual fingers while manipulating a yo-yo.2021ATAkifumi Takahashi et al.University of Chicago, The University of Electro-CommunicationsElectrical Muscle Stimulation (EMS)CHI
Double-sided Printed Tactile Display with Electro Stimuli and Electrostatic Forces and its AssessmentHumans can perceive tactile sensation through multimodal stimuli. To demonstrate realistic pseudo tactile sensation for the users, a tactile display is needed that can provide multiple tactile stimuli. In this paper, we have explicated a novel printed tactile display that can provide both the electrical stimulus and the electrostatic force. The circuit patterns for each stimulus were fabricated by employing the technique of double-sided conductive ink printing. Requirements for the fabrication process were analyzed and the durability of the tactile display was evaluated. Users’ perceptions of a single tactile stimulus and multiple tactile stimuli were also investigated. The obtained experimental results indicate that the proposed tactile display is capable of exhibiting realistic tactile sensation and can be incorporated by various applications such as tactile sensation printing of pictorial illustrations and paintings. Furthermore, the proposed hybrid tactile display can contribute to accelerated prototyping and development of new tactile devices.2018KKKunihiro Kato et al.Meiji UniversityVibrotactile Feedback & Skin StimulationShape-Changing Interfaces & Soft Robotic MaterialsCHI