AsymDrive: Fingertip-Free Force Illusions Induced by Asymmetric Vibrations on Dorsal-Palmar Tendons

Force feedback to the hand is essential for enhancing immersion in VR and facilitating skill transfer. However, no existing method allows unconstrained hand and arm positions while keeping the fingertips free. We present a novel fingertip-free technique that induces directional force illusions on the entire hand by applying asymmetric vibrations to antagonistic dorsal and palmar tendons. Through two user studies, we demonstrate that directional accuracy is significantly above chance level under dual-point asymmetric vibration, in contrast single-point or symmetric vibration. By integrating effective haptic feedback with unconstrained hand interaction, our approach offers a promising avenue toward richer VR experiences.