The rapid development of nano technology and mobile devices has created high demand for shape changing mobile devices in order to provide users with more functions in less space and improved usability. However, the fundamental incompatibility between flexible displays and rigid actuator components has brought a huge barrier for commercialization of this technology. This paper presents a flexible and bendable vibrotactile actuator that can be easily applied to shape changing mobile devices. The proposed vibrotactile actuator is made with an electro-conductive membrane based on polyurethane, a base membrane, and an airgap. Actuation of the proposed actuator is controlled by a polarity of both charged membranes and the actuator performance can be modulated by increasing level of biased electric potential. A user experiment showed that the proposed actuator can provide vibrations with sufficient strength for perception.

This paper proposes a new interactive interface TAXEL, which aims at developing a reconfigurable self-morphing visio-haptic interface. We first present the overall architecture and concept of a self-morphing visuo-haptic interface. Key hardware components are developed and tested, including three tactile actuators using a piezoelectric active linear actuator, a passive MR fluid actuator, and a thin film-type actuator, respectively, and a flexible visual display based on the light-waveguide technology. Using the developed components, a tactile platform that includes a 8×16 array of the linear actuators is implemented for a proof of concept. A rendering engine is also designed for the tactile platform with emphasis on the use of haptic feedback together with GUI. We also carried out a user study with virtual button simulation as a benchmark to evaluate the performance of the TAXEL tactile platform. Lastly, an integrated system with a visual display is demonstrated along with several application examples.

This paper presents a new subminiature impact type actuator which creates the haptic sensation in a mobile device. Recently, linear resonance actuators (LRA) are widely used. One of the key differences between an LRA and a traditional eccentric motor is that the LRA generates the vibrotactile sensation through resonance for minimizing response time. The strategy of operation near the resonant frequency, however, brought a new issue for creating vibrotactile sensation which can be strong enough to feel in arbitrary frequency. In order to achieve this issue, we adopt an unstable structure to amplify impact force and to reduce response rate. Due to the impact with fast rising and falling time in the proposed impact actuator, the available strong impact vibration is created over wide frequency range from 0Hz to 100Hz. The impact vibration generated from the proposed actuator is suitable for reproducing realistic button sensation and creating various vibration patterns in mobile devices.

In this paper, multi-fingered tactile display modules are proposed. Each tactile display module is comprised of a 4 times 4 piezoelectric ultrasonic actuator array with a spatial resolution of 1.5 mm and a temporal resolution of 20 Hz. The objective of this research is to build a small and lightweight tactile display system so that the system including the display modules and complete controller parts is wearable by a user. It was found that various types of texture information can be generated using a static indentation or through the vibration of each pin. Three tactile display modules were utilized for interaction with a 3D virtual environment. As the developed tactile display modules consume less power and are connected wirelessly to a host PC, the system is applicable to various types of texture representation systems.

In this paper, a compact tactile display which consists of multiple vibrotactile actuators with 4-different vibrotactile unbalanced masses and a Peltier thermoelectric module is proposed. By stimulating 2 different sensory channels including mechanoreceptors and thermoreceptor simultaneously, surface texture and material composition can be displayed using the implemented device. 3 experiments were conducted for the performance evaluation of the proposed device through discriminating various patterned textures. Experimental results show that the developed device can be used to display surface texture and temperature together and suggest the possibility of implementing a small-sized, multi-fingered tactile display device.