The most common method of presenting tactile stimuli to touch screens has been to directly attach a tactile display to the screens. This requires a transparent tactile display so that the view is not obstructed. In contrast, transparency is not required if the tactile stimuli are presented on the back of the device. However, stimulating the entire palm is not appropriate because touch screens are typically used by only one finger. To overcome these limitations, we propose a new method in which tactile feedback is delivered to a single finger on the back of a touch screen. We used an electro-tactile display because it is small and dense. The tactile display presents touch stimuli as mirror images of the shapes on the touch screen. By comparing cases in which the device was operated by one or two hands, we found that shape discrimination is possible using this method.

It is known that visual, auditory, and tactile modalities affect the experiences of eating and drinking. One such example is the “glug” sound and vibration from a Japanese sake bottle when pouring liquid. Our previous studies have modeled the wave of the vibration by summation of two decaying sinusoidal waves with different frequencies. In this paper, to enrich expression of various types of liquid, we included two new properties of liquid: the viscosity and the residual amount of liquid, both based on recorded data.

We developed a bed-style haptic display "Haptic Bed" that provides weight sensation to wide area of the user's body. This system comprises motors, belts, a cushion and a comforter to press and swing the user lying on the bed. Haptic Bed is a type of whole-body haptic interface, characterized by the presentation of low-frequency force with multiple degrees of freedom. The prototype system with two motors can present a weight sensation to approximately five regions of the abdomen. Although a sensation is only presented to the abdomen in this study, Haptic Bed can present a weight sensation to a wider area by increasing the number of motors. The system has the potential to enrich the audio visual experience in several ways, such as by expressing the sensation of a horrific ghost sitting on the user as part of entertainment content, or by presenting the existence of a remote relative as a telecommunication tool. Overall, the system changes a bed into a new medium through which immersive contents are presented in an immersive manner.

With the aim of augmenting auditory sensation by tactile stimuli, we investigated cross-modal relationships between the two modalities, focusing on frequency. The results showed that frequency consonance between tactile and audio stimuli depends on the relationship between harmonics, in a manner similar to auditory waves, but with broader peaks.

We propose a tactile enhancement structure inspired by hair follicle receptors. Unlike other receptors, part of the hair follicle receptor is exposed to the outside. Recent research has shown that skin hair contributes to perception of minute forces that cannot be perceived with glabrous skin. We considered how the skin perceives these minute forces. Our tactile enhancement device mimics the structure of hair follicle receptors. A matrix structure simulating artificial body hair is driven by minute forces external to the skin surface. This structure can be used on any surface of the human body because it is fully composed of passive elements.