Acoustic Finger Force Measurement with Lateral Ultrasonic Surface Haptic Devices for Friction Reduction Estimation

When the finger interacts with a surface where a purely lateral ultrasonic vibration occurs, a vibration attenuation is produced. An added force is therefore needed in order to maintain the vibration amplitude in closed loop control. In this article we explore whether the friction reduction in lateral ultrasonic surface haptic devices may be predicted using static measurements of this additional force.