A Review of Smart Materials in Tactile Actuators for Information Delivery

As the largest organ in the human body, the skin provides the important sensory channel for humans to receive external stimulations based on touch. By the information perceived through touch, people can feel and guess the properties of objects, like weight, temperature, textures, and motion, etc. In fact, those properties are nerve stimuli to our brain received by different kinds of receptors in the skin. Mechanical, electrical, and thermal stimuli can stimulate these receptors and cause different information to be conveyed through the nerves. Technologies for actuators to provide mechanical, electrical or thermal stimuli have been developed. These include static or vibrational actuation, electrostatic stimulation, focused ultrasound, and more. Smart materials, such as piezoelectric materials, carbon nanotubes, and shape memory alloys, play important roles in providing actuation for tactile sensation. This paper aims to review the background biological knowledge of human tactile sensing, to give an understanding of how we sense and interact with the world through the sense of touch, as well as the conventional and state-of-the-art technologies of tactile actuators for tactile feedback delivery

Tactile to vibrotactile sensory feedback interface for prosthetic hand users

The motivation of this research work is to provide a sense of embodiment to prosthetic users by supplementing their devices with sensory feedback to the residual upper arm. This sensory feedback replicates the tactile sensory system of glabrous skin that covers palm and flexor surfaces of fingers. In this work, we produced vibration patterns that will be perceived at the upper arm, according to signals obtained by a prosthetic finger when sliding across fabricated textured surfaces. This was done by transforming the signals to ‘on’ and ‘off’ pulses in the LabView environment and then forwarded to a data acquisition board to provide voltage signals to a vibration actuator. We implemented a novel frequency measurement procedure to maintain a vibration frequency of 250 Hz, which is the optimum frequency of the mechanoreceptors underneath the skin of the upper arm in detecting vibration. The outcome from this research work leads to optimistic possibility that a touch sensation that was previously lost could be restored to different parts of the body. This undoubtedly will increase users’ acceptance of the device as a part of their body due to its ‘lifelike’ quality

ヒトの高周波振動知覚の類似特性に基づく触覚変調

Tohoku University昆陽雅司課

Haptics: Science, Technology, Applications

This open access book constitutes the proceedings of the 13th International Conference on Human Haptic Sensing and Touch Enabled Computer Applications, EuroHaptics 2022, held in Hamburg, Germany, in May 2022. The 36 regular papers included in this book were carefully reviewed and selected from 129 submissions. They were organized in topical sections as follows: haptic science; haptic technology; and haptic applications

Development of a Multiple Contact Haptic Display with Texture-Enhanced Graphics

This dissertation presents work towards the development of a multiple finger, worn, dynamic display device, which utilizes a method of texture encoded information to haptically render graphical images for individuals who are blind or visually impaired. The device interacts directly with the computer screen, using the colors and patterns displayed by the image as a means to encode complex patterns of vibrotactile output, generating the texture feedback to render the image. In turn, the texture feedback was methodically designed to enable parallel processing of certain coarse information, speeding up the exploration of the diagram and improving user performance. The design choices were validated when individuals who are blind or visually impaired, using the multi-fingered display system, performed three-times better using textured image representations versus outline representations. Furthermore, in an open-ended object identification task, the display device saw on average two-times better performance accuracy than that previously observed for raised-line diagrams, the current standard for tactile diagrams