When presented with asymmetric vibrations, humans typically experience an illusory force that is similar to the sensation of being pulled toward a particular direction. The pulling illusion has been used in new display elements for a pedestrian navigation system and a VR content because the asymmetric vibrations can be implemented in a small non-grounded device. This paper reviews the findings of the pulling illusion with covering a wide range of topics, including the basic concept, physiological mechanism, optimal parameters for the illusion, the control method of force vectors, the evaluation method of the illusion, and applications. As a result of the review, the research trend of the pulling illusion was confirmed, and the vital points which were stimulation method and parameters of asymmetric vibration to design a haptic interface using the illusion were clarified.

We propose ThermalBitDisplay, which is a haptic display with tiny Peltier devices providing thermal feedback perceived differently depending on the parts of the body touching them. We focus on the different thresholds of thermal sensitivity of body parts and the spatial summation of thermal perception. Utilizing these characteristics, for example, enables providing thermal feedback perceived only on the lips, not on other parts of the body. We conducted user studies with 12 participants to investigate the different thermal sensitivity between different body parts on which weak thermal stimulation was presented with tiny Peltier devices. Based on the results, we propose some applications with ThermalBitDisplay for pull notifications, affective communication, and haptic alerts.

How can visually impaired people enjoy watching sports and share excitement with his/her friends? Although sharing emotion is one of essential factor in sports viewing, they cannot notice other’s emotional reactions, and consequently often feel isolated. Here we propose a sports watching method using a concise haptic device for sharing excitement. The haptic device comprise two balls and a tube connecting them, and can transmit air from a ball to the other by holding a ball firmly. When two users hold a ball at each end, the users can share excitements by sending air.

A number of studies have demonstrated a visual enhancement of touch (VET) effect. Such effect shows viewing the body enhances tactile acuity. Although there is sufficient evidence that visible area and visual scale influence tactile perception, the extent to which visual properties uniquely modulate the effect is not fully understood. Despite its importance in visual processing, how visual resolution affects the VET effect has not been investigated. In the present study, we investigated whether viewing the body at a reduced resolution abolishes the VET effect. Our results demonstrate that visual resolution of the body also modulates the enhancement of tactile performance, since vision of the body at a reduced resolution worsens tactile discrimination acuity compared with seeing the body normally.

Enhancing a user’s sense of presence and immersion with haptic technologies has recently been getting increasing attention in virtual reality. Yet while several devices that use wind as a haptic modality have been proposed, it is difficult to precisely and quickly control the stimulation of the wind. In this study, we tackle creating an illusion of wind blowing with multiple air cannons that provides low-latency tactile sensations based on the perception of apparent tactile motion. We conducted an experiment to investigate the occurrence of the wind blowing sensation and the optimal parameters. Based on the results, we have exhibited a demonstration by synchronizing with the sound source movement to show the possibility of creating a sense that virtual objects passed in front of the participants.

In this paper, we propose a method to improve tactile sensitivity and manual dexterity of the finger pads by presenting weak vibrations to the fingernails. Since the vibrator is mounted on the nail, it does not obstruct the tactile perception of the finger pad. In addition, the intensity of the vibration can be small because the vibration is transmitted from close to the finger pad. This enables the use of a small piezo resonator that fits over the pawl and does not interfere with manual work. First, tactile sensitivity of the finger pad was evaluated by a roughness discrimination test using sandpaper, and the correct answer rate was significantly improved when vibrations of the same intensity as the perception threshold were presented to the nails. Next, manual dexterity was evaluated using a hand task with a grooved pegboard, and task completion time was significantly improved when a threshold vibration was applied to the nail. These results showed that both tactile sensitivity and manual dexterity of the finger pad were improved by weak vibrations to the fingernails. The reason for this result seems to be that the weak vibrations improved the haptic feedback capability during the manual work. These results suggest that the proposed method has the potential to support manual work mainly using the fingertips.

Ontenna is a device that can be worn on the hair, earlobe, collar, or sleeve, and it transmits sound characteristics to the human body through vibration and light. It can serve as an auxiliary acoustic sensory device for hearing-impaired people, whereas for others, it can serve as a novel acoustic perception device. A condenser microphone mounted on the main body of Ontenna acquires the sound pressure and drives the vibration motor and light emitting diode in real-time according to the input signal. This allows the user to perceive various sonic features such as the rhythm, pattern, and strength of sound. Furthermore, by simultaneously controlling several Ontenna devices through a controller, a rhythm can be transmitted to each user. In this paper, we present the inclusive design of Ontenna for hearing-impaired people, along with the design process of Ontenna, which was improved through digital fabrication. Additionally, in this paper, we present case studies regarding the usage of Ontenna in a hearing-impaired school and case studies on Ontenna’s application in the field of entertainment for hearing-impaired people and others.

This paper proposes an electrostatic tactile paper with colored ink printed on solid electrodes, and that can express both visual and tactile stimulation. The display was constructed on flexible film, making it easy to fold and store. As a result, it was compact and portable. The display is made up of a flexible film that can be folded for storage. It is also easy to make the display larger. In this paper, we discuss the possibility of using the display to present a tactile sensation of uniform intensity over a large area. We also investigated options for the size of the contact area and examined the effect of size of the colored ink layer on perceptual intensity. The results showed that uniform presentation of tactile stimulation was possible, at least at the A3 size. We also found that sensitivity to the tactile stimulation increased when the whole hand was in contact with the display. Although the presence or absence of the colored ink modulated the intensity of the perception, the thickness of the ink layer had no effect. Our results indicate that it is possible to print vivid graphics using a sufficient amount of ink without worrying about the effect on tactile presentation. In summary, the effectiveness of both visual and tactile presentation using the proposed display was confirmed.

In this paper, I propose a 7DOF wire driven haptic device for natural grasping. The haptic device provides not only the force sensation of the translation and rotation of the end-effector with 6DOF, but also the force sensation with grasping as 1DOF. It is necessary to drive an end-effector with n+1 strings or more in order to realize a string based haptic device with nDOF. In this research, eight strings allow the haptic device to realize the 7DOF. In order to verify the proposed method, computer simulation was performed on the measurement of manipulability of the proposed design based on manipulability ellipsoid and displaying force range. The proposed haptic device was developed. As an evaluation experiment of the proposed system, grip and rigid body operations were measured in VR world. As a result, it was confirmed that the device generate the grasp force and the manipulating force simultaneously. It is possible to display high tracking and force ability to the VR object.

The spread of game engines has enabled many engineers to efficiently create VR applications. However, development tools for VR applications with force-feedback application development. In particular, there are few tools for presenting haptic sensation of touching soft object for force display of soft objects. Namako supports physical simulation based on finite element method and force display using virtual coupling. Furthermore, it provides a GUI for mesh importing and physical parameter setting to help efficient application development. Using Namako, we were able to design the haptic sensation including the stiffness and friction of game engine such as high quality graphics rendering, interactive scene editing, publicity available assets developed by the game engine community, and so on. This paper presents an example of development workflow using Namako, performance evaluation of implemented physics simulator and force display controller, and several haptic VR applications developed by the authors.

A physical reliving experience system for craftsmanship can be useful in sales promotion and training. In particular, an asynchronous system that incorporates videos can be employed for sharing the experience with multiple users at a low cost. However, the users of such a system cannot acquire a sense of ownership and agency. Hence, in this study, we propose a system that creates an illusory sense of ownership and agency by presenting vibration stimuli that are synchronized with the video and by following the user’s hand movement to the corresponding video motion. The obtained results indicate that the proposed system improves the user’s sense of ownership and agency. Furthermore, sense of ownership and agency improve when the same motion is repeated, even if there is a discrepancy between the video and user’s hand motion.

We propose StickyTouch, a novel tactile display that represents an adhesive information. This adhesive surface is capable of manipulating the degree of adhesion, enabling new kinds of interactions such as attaching and detaching the user’s fingers. Adhesion control is achieved with a temperature sensitive adhesive sheet whose temperature is locally controlled by Peltier devices arranged in a grid. In this paper, we describe the details of principle and system design of StickyTouch, and discuss the implementation of a proof-of-concept prototype with 64 Peltier devices with an adhesive size of 150×150 mm. We conduct several experiments on adhesion perception when touching and swiping on the display surface to evaluate the performance of StickyTouch. Finally, we discuss the applications for touch and swipe and our future prospects.

This paper proposes a novel method to design a virtual coupling for impedance display system in haptic interface with. This method uses fractional derivative terms to design desired passivity distribution along frequency range. First, we discuss the property of single fractional derivative term. Then, we proposed a method using multiple fractional derivative terms and to optimize the parameters to realize a desired passivity distribution. In order to omit the laborious operation in the design process, we also constructed a VC-Sample with which users can feel the interaction and can obtain the parameters in various VCs. Finally, we performed experiments to show the effects of VCs on the VC-Sample.

In this paper, we propose a tactile display with multiple stimulus elements that present rotational shear deformation on the skin, and describe the design of a device that applies the proposed method to the back. Shear deformation stimulation to the skin can be used to perceive force in a small device, and numerous methods have been proposed. Among them, methods that present the distribution of spatial shear stimuli are expected to be a method to reproduce skin sensations with high reality. In this study, we propose a tactile display with multiple stimulus elements that present rotational shear deformation to the skin using a rotating motor. A rotary motor is a widely used actuator that is easy to control, and can be scaled to apply to various body parts. In this paper, we design a device that can present the distribution of shear deformation stimuli in the back as an example of the application of this method. In particular, we focused on the size of the rotating tactors and the distance between the tactors among the form factors, and conducted a perception experiment. It was found that when the size of the tactor was 20mm, the direction of rotation was not perceived and the dynamic range of the intensity of the stimulus was maximized, and spatially continuous stimuli could be presented to the back if the distance between the tactors was 60mm or less.

This paper presents “Public Booth for Vibrotactile Communication”, an interactive audio-visual-haptic media that allows us to feel the vibrations of the other people who share the same desk and face each other. The purpose of this research is to observe what kind of behavior people take when a higher presence is presented by tactile sensation in telecommunication. As the interface, we designed a pair of frames consisting of a curved screen to show the upper body and the hand of a life-size person, a haptic system to share tactile sensation, and a sound system. By installing the frames in multiple remote places and transmitting audio-visual-tactile sensation interactively, we observed what kind of behavior faced people do and what kind of communication was created between them. As a result, various haptic plays were created. Since the tendency in the development of haptic communication observed in the developmental phase of infants was also observed through this approach, it was clarified that the heightened presence provided by haptics for telecommunication contributes to the promotion of friendship.

The glare-illusion is a well-known illusory perception that a region appears brighter than its actual luminance when surrounded by a gradation of luminance. Its illusion has the potential to gives strong shine perception than the naive enhancement in projection display. This paper proposes a novel projection-based perceptual shine enhancement method based on the glare illusion to break manipulation limitations caused by hardware performance. Our proposed method generates an overlay illumination pattern which has gradation surrounding the specular region to induce glare illusion. Through the experiments, we confirmed the proposed method gives a brighter perception than naive contrast enhancement. The remaining issue is a study on the optimal gradation width for each scene.

We propose a method for presenting a wide viewing-angle stereoscopic aerial image using multiple displays and semi-symmetrical mirrors. In recent years, research on aerial images has been active, and application to entertainment and interfaces are expected. However, the recent popular Micro-Mirror Array Plates are far from practical use due to lack of stereoscopic effect and narrow viewing angle. Therefore, in this research, we present a MMAPs-based wide viewing-angle stereoscopic aerial imaging. A wide range of 3D shapes are divided and displayed with multiple displays, and they are merged into a single aerial image by using MMAPs and some mirrors.

The gaze direction and face orientation of a person depicted in a portrait painting appear to follow the view-point of observers when they move parallel to the portrait. This is called the Mona Lisa effect. In this study, we examined the role of “faceness”, the degree an object looks like a face, in the Mona Lisa effect by measuring the subjective width of the depicted face. Through a series of experiments, we showed that the Mona Lisa effect is stronger for upright than for upside-down faces, but it has about the same strength for photographic negative faces as for photographic positive faces. These results suggest that the Mona Lisa effect depends on “faceness” and the configuration of facial parts (facial pictorial cues) is critical for this effect.

Supernumerary robotic arms are able to increase degree of freedoms which human has, but it requires a control method reflecting intention of the operator. To control the arms accord with the intention of the operator, we propose an operation method with his/her facial expressions. We propose to map facial expressions to supernumerary robotic arms operation. To measure facial expressions, we used a optical sensor-based approach (here inside a head-mounted display), the sensors data are fed to a SVM classifying them in facial expressions. The supernumerary robotic arms can then carry out operation by predicting the operator’s facial expressions. We made a virtual reality environment with supernumerary robotic arms and synchronizable avatar to investigate the most suitable mapping between facial expressions and supernumerary robotic arms.