Displacement Observation of Skin phantom by Laser Displacement Meter for Direct Measurement

Haptics constitutes a pivotal research domain intertwined with the sense of touch. Traditionally, discussions revolving around haptic actuators predominantly fixated on the quantification of generated forces, encompassing acceleration and acoustic radiation pressure. Yet, the effectiveness of transmitting these generated forces to the skin remained ambiguous. This study undertakes the task of elucidating this concern by employing a laser displacement gauge to directly quantify the skin displacement induced by ultrasonic haptic actuators’ acoustic radiation pressure.By using the actuator with the high sound pressure up to 4000 Pa, the displacement traits of the synthetic skin phantom, revealing discernible displacements ranging from $300 \mu \mathrm{m}$ down to several hundred nanometers. Furthermore, the displacement traits acquired exhibit a tendency to correlate with the viscoelastic model of the skin. t traits acquired exhibit a tendency to correlate with the viscoelastic model of the skin. This shows that the currently devised model can be used over a wider range of displacements than existing studies.