HapCube: A Wearable Tactile Device to Provide Tangential and Normal Pseudo-Force Feedback on a Fingertip

Haptic devices allow a more immersive experience with Virtual and Augmented Reality. However, for a wider range of usage they need to be miniaturized while maintaining the quality of haptic feedback. In this study, we used two kinds of human sensory illusion of vibration. The first illusion involves creating a virtual force (pulling sensation) using asymmetric vibration, and the second involves imparting compliances of complex stress-strain curves (i.e. force-displacement curves of mechanical keyboards) to a rigid object by changing the frequency and amplitude of vibration. Using these two illusions, we developed a wearable tactile device named HapCube, consisting of three orthogonal voicecoil actuators. Four measurement tests and four user tests confirmed that 1) a combination of two orthogonal asymmetric vibrations could provide a 2D virtual force in any tangential directions on a finger pad, and 2) a single voicecoil actuator produced pseudo-force feedback of the complex compliance curves in the normal direction.