Perceptual and biomechanical frequency response of human skin: implication for design of tactile displays

This paper investigates spatiotemporal tactile perceptive characteristics and biomechanical properties of human skin and considers their implications for the design of tactile displays. Three separate experiments were conducted. First, we measured vibrotactile thresholds as a function of frequency of vibration, using a cylindrical contactor of 0.7 mm diameter. The results of our experiment showed similar trends to that of previous physiological results that used a larger contactor. In the second experiment, vibrotactile spatial acuities were investigated. Two-point localization errors were measured on the tip of the index finger and on thenar eminence as a function of frequency of vibration. The results show that human skin is sensitive to spatial differences at the frequency bands of 1-3 Hz and 18-32 Hz. The subjects' spatial acuities gradually decreased as the frequency of vibration increased over 50 Hz. In the third experiment, impedances of human skin were measured as a function of frequency of vibration. From these results, we discuss the implications in the designing of spatially distributed tactile displays and methods for texture display.