Haptic displays play an important role in enhancing the sense of presence in VR and telepresence. Displaying the tactile properties of fabrics has potential in the fashion industry, but there are difficulties in dynamically displaying different types of tactile sensations while maintaining their flexible properties. The vibrotactile stimulation of fabrics is an important element in the tactile properties of fabrics, as it greatly affects the way a garment feels when rubbed against the skin. To dynamically change the vibrotactile stimuli, many studies have used mechanical actuators. However, when combined with fabric, the soft properties of the fabric are compromised by the stiffness of the actuator. In addition, because the vibration generated by such actuators is applied to a single point, it is not possible to provide a uniform tactile sensation over the entire surface of the fabric, resulting in an uneven tactile sensation. In this study, we propose a Pinching Tactile Display: a conductive cloth that changes the tactile sensation by controlling electrostatic adsorption. By controlling the voltage and frequency applied to the conductive cloth, different tactile sensations can be dynamically generated. This makes it possible to create a tactile device in which tactile sensations are applied to the entire fabric while maintaining the thin and soft characteristics of the fabric. As a result, users could experiment with tactile sensations by picking up and rubbing the fabric in the same way they normally touch it. This mechanism has the potential for dynamic tactile transformation of soft materials.

We present FoodSkin, a technique for adding interactive elements to foods by implementing edible circuits on the surface of the food. The circuit is easily fabricated using commercially available materials. Existing approaches to enhance the eating experience, such as presenting an electrical taste by making food part of an electronic circuit, are challenging to apply to foods with low water content due to their low conductivity. Our technique enables the integration of dry foods into an electronic circuit and provides displaying (e.g., smell or taste) and sensing (e.g., eating activity) functionalities. We describe our fabrication technique with a library of food materials that we can utilize, evaluate the conductivity and adhesion of the gold-leaf traces, introduce demonstrative applications, and conclude with a workshop we conducted to evaluate the accessibility of our technique. FoodSkin enriches the design space for the computer-augmented eating experience by enabling the digital fabrication of electronics on versatile materials, surfaces, and shapes of foods.

Gastroenterological endoscopic surgery needs complex surgical skills such as a sensation of body movement and manipulation of the endoscope that is hard to be explained verbally. Prior research reported that endoscopic surgery is one of the most challenging surgery to teach. Thus, surgeons need long-term practice to master the skills. To support learning such skills, we developed a surgical scene replay system. First, we surveyed 12 surgeons to reveal the reason for the difficulty and elicited three requirements for our system: (1) provide multiple videos that include an endoscope, a fluoroscopy, and hand manipulation for the endoscope to observe the surgery from multiple aspects; (2) visualize an experts' gaze position to understand experts' intention of hand manipulation, and (3) enlarge the size of the gazed video to inform learners where they should pay attention to. Our user study with the system indicates that participants could understand the experts' intentions and tacit knowledge easier than the existing video materials.

One of the most difficult things in practicing musical instruments is improving timbre. Unlike pitch and rhythm, timbre is a high-dimensional and sensuous concept, and learners cannot evaluate their timbre by themselves. To efficiently improve their timbre control, learners generally need a teacher to provide feedback about timbre. However, hiring teachers is often expensive and sometimes difficult. Our goal is to develop a low-cost learning system that substitutes the teacher. We found that a variational autoencoder (VAE), which is an unsupervised neural network model, provides a 2-dimensional user-friendly mapping of timbre. Our system, SonoSpace, maps the learner's timbre into a 2D latent space extracted from an advanced player's performance. Seeing this 2D latent space, the learner can visually grasp the relative distance between their timbre and that of the advanced player. Although our system was evaluated mainly with an alto saxophone, SonoSpace could also be applied to other instruments, such as trumpets, flutes, and drums.

The human body has unique electrical characteristics. These characteristics have been investigated in various studies in human-computer interaction (HCI) and related research fields. Such studies include applications for using the body as a conductive lead for transmission or electric field sensing and activating human muscles or organs. However, electricity is not completely safe for the human body; therefore, to avoid harming users, careful consideration is essential when developing such devices. The knowledge required for such consideration is spread throughout a large number research fields, and it can be difficult for researchers in the HCI field to comprehend all of them. The purpose of this article is to support researchers in developing systems that apply electricity to the human body and to serve as a basis for further research. This article reviews previous research pertaining to HCI in which users come into contact with electricity. In addition, considerations of how and where this type of research can be expanded, along with guidelines grounded in other fields for designing systems safely and addressing ethical concerns, are presented. An understanding of the field and of the related safety issues will enhance the understanding of limitations and potential and can clarify the design space.

Electric taste is a characteristic taste produced when the tongue is electrically stimulated. We have proposed apparatuses to add electric taste to food and drink. An interactive system could be developed to synchronize video contents using the reversibility and instantaneity of electric taste. However, to do so, the presentation time must be determined based on the different latency for the perception of each sense. We measured the latencies for electric taste and visual stimuli as a basic evaluation for a content presentation system in which electric taste and visual content are synchronized.