Haptic Display Responsive to Touch Driven by Soft Actuator and Soft Sensor

Abstract

Haptic display transfers the sense of touch by applying forces, vibrations, or motions to the user. This article presents a novel bidirectional haptic display responsive to touch. The device is composed of a flexible tactile sensor and tactile actuator, and the actuator is actuated according to the touch signals from the tactile sensor. The tactile sensor is a thin array of resistive type sensors that covers the top of the soft dielectric elastomer actuator array. The tactile sensor measures the normal forces (0<inline-formula><tex-math notation= LaTeX >$-$</tex-math></inline-formula>6 <inline-formula><tex-math notation= LaTeX >$N$</tex-math></inline-formula>) and positions of touches and then sends these signals to control the corresponding tactile actuator cells. The tactile actuator works within the frequency range of 0<inline-formula><tex-math notation= LaTeX >$-$</tex-math></inline-formula>300 Hz, provides up to 520 <inline-formula><tex-math notation= LaTeX >$\\mu \\text{m}$</tex-math></inline-formula> of displacement and, 600 mN of normal force, much greater than the human hand threshold (50 mN). And thus, the device can transfer different feelings to users. In this research, we develop and evaluate a stand-alone bidirectional haptic display. Then, we took the psychophysical test and introduced the master—slave system whereby the master device controls the slave device depending on the master input.