Evaluation of Multi-Electrode Effects on Electrovibration Tactile Stimulation

Abstract

Electrovibration is one of promising methods for tactile feedback in mobile devices because of its simplicity of the structure and principle. In order to increase the capability of tactile presentation with the electrovibration, we developed an electrovibration tactile display with 1 mm electrode resolution. Voltage to each electrode is controlled separately and the tactile display can present electrovibration stimulus distribution. We designed the tactile display and optimized the voltage waveform to avoid destruction of an insulator. We fabricated the proposed tactile display with micro-fabrication process. We experimentally evaluated the relationships between stimulation condition and perception in subjects. The obtained results indicated that the multi-electrode design had a potential to enhance tactile rendering performance of electrovibration stimulation.

Fundamental Perceptual Characterization of an Integrated Tactile Display with Electrovibration and Electrical Stimuli

“…The values were not largely changed under high-frequency conditions. The obtained trend was similar to the results of related studies [25,26]. One considerable reason for this trend is the attenuation of the applied voltage induced by the skin and devices [25].…”

“…The width and length of electrodes for each stimulus were 0.9 mm and 18 mm, respectively. The electrode designs were determined on the basis of the results of related studies, considering the spatial stimulation [26,27]. A pad for electrical connection was formed at the end of the electrode.…”

Evaluation of Electrovibration Stimulation with a Narrow Electrode

“…The threshold voltage was almost constant at 80 Hz or higher. Previous studies have revealed that the tactile perception to electrovibration is almost constant at high frequency [ 24 , 25 , 30 ]. We also confirm the same trend, although the size of the electrode was narrower than that of the previous studies.…”

“…The applied voltage to each electrode was a pulse wave. The duty ratio of the applied voltage was 10% to avoid breakdown of the insulator layer [ 30 ]. It was possible to vary the peak voltage from 0 V to 600 V with the scroll bar of the evaluation system.…”

“…There have been few studies dealing with multi-electrode electrovibration tactile displays [ 21 , 22 , 23 , 30 ]. However, the sizes of the evaluated electrodes were of millimeter-order and an electrode with a size of a few hundred micrometers or less has never been developed and evaluated.…”