Development of a piezoelectric actuator for presentation of various tactile stimulation patterns to fingerpad skin

In order to investigate tactile perception characteristics of the human fingerpad for the optimal design of a sensory substitution system, we have developed a small piezoelectric bimorph actuator that possesses flat frequency characteristics in the vibratory frequency of tactilely perceivable bandwidth. The parameters for the design of the bimorph were determined by using a mechanical simulation model of a piezoelectric bimorph and a fingerpad skin. To evaluate the performance of the bimorph, we measured frequency-displacement relationships when the skin of a fingerpad was vibrated by the piezoelectric bimorph. The experimental results showed that the frequency-displacement relationships were almost the same as the estimation obtained from the mechanical simulation model.