Augmentation of Material Property by Modulating Vibration Resulting from Tapping

We present a new haptic augmented reality system that modulates the perceived stiffness of a real object by changing the perceived material with vibratory subtraction and addition. Our system consists of a stick with a vibrotactile actuator and a pad with an elastic sheet. When a user taps the pad, the innate vibration resulting from the tapping is absorbed by the elastic surface. Simultaneously, the vibrotactile actuator provides the intended vibration, which represents a modulated perceived material property such as rubber, wood, or aluminum. The experimental results showed that the participants were able to discern the three materials by tapping.