Norihisa Miki

Demonstration of Vibrational Braille Code Display Using Large Displacement Micro-Electro-Mechanical Systems Actuators

In this paper, we present a vibrational Braille code display with large-displacement micro-electro-mechanical systems (MEMS) actuator arrays. Tactile receptors are more sensitive to vibrational stimuli than to static ones. Therefore, when each cell of the Braille code vibrates at optimal frequencies, subjects can recognize the codes more efficiently. We fabricated a vibrational Braille code display that used actuators consisting of piezoelectric actuators and a hydraulic displacement amplification mechanism (HDAM) as cells. The HDAM that encapsulated incompressible liquids in microchambers with two flexible polymer membranes could amplify the displacement of the MEMS actuator. We investigated the voltage required for subjects to recognize Braille codes when each cell, i.e., the large-displacement MEMS actuator, vibrated at various frequencies. Lower voltages were required at vibration frequencies higher than 50 Hz than at vibration frequencies lower than 50 Hz, which verified that the proposed vibrational Braille code display is efficient by successfully exploiting the characteristics of human tactile receptors.

20pm3-PM013 Creation and evaluation of virtual surfaces by a tactile sensor coordination

In this paper, we demonstrate encoding of a surface texture and displaying it to a subject using a MEMS-based tactile display. The tactile display is composed of a piezoelectric actuator array and hydraulic displacement amplification mechanism. We now use the display to encode, or copy, the surface texture by sliding the surface on the display. The obtained waveforms from the piezoelectric actuator array, which worked as the sensor array, was, in turn, amplified to drive the actuator arrays to display the surface texture to the subject whose fingertip was placed onto the display. We successfully copied the surface textures of samples and could even blend the surfaces to create new surfaces with various hardness and roughness. The proposed system is readily applicable to advanced human-computer interactions.