We present the Finger-Mounted Extending Rod, a wearable device that transforms fingers into virtual tools by modulating fingertip mass distribution. We employ linear actuators on fingers that extend or retract metal rods according to their poses, generating rotational inertia while redirecting the hand to natural grip postures. Through three user studies, we evaluate (1) finger pose embodiment under visual redirection and tool matching via inertia tensor similarity, (2) perception of tool length and rotational inertia, and (3) VR tool interaction experience. Results show that 10 of 15 finger poses maintained embodiment, exhibiting inertia tensor similarities of 0.936–0.991 with their matched tools and yielding perceived inertia amplifications of 4.19–10.45×; moreover, aligning inertia tensors to virtual tools enhanced immersion, realism, and enjoyment compared to misaligned or no-device conditions across six VR scenarios. We conclude by discussing how the system renders virtual tools through the fingers and enhances their perception with inertia modulation.

In-car VR applications typically synchronize virtual motion with real vehicle movement to minimize visual-vestibular mismatch. However, this approach limits virtual movement to directions in which the vehicle can physically move, typically restricting the experience to horizontal motion. This study introduces a method to expand the range of virtual motion by simulating vertical movement, leveraging vehicle acceleration to induce a vertical pitch illusion via manipulation of gravitoinertial perception. We conducted a two-phase study evaluating (1) optimal vertical gain values for maximizing perceptual realism in a controlled environment and (2) user experience factors such as motion sickness and presence in an on-road VR flight simulation under realistic driving conditions. Our findings show that users tend to prefer vertical gains that exceed theoretically valid mappings, and highlight the importance of aligning virtual motion with perceived inertial cues to enhance the realism and coherence of vertical motion in in-car VR applications.

This paper presents a tiny haptic interaction module which generates high resistive torque for VR fishing leisure activity. The presented haptic interaction module was developed by magnetic rheological fluids and optimizing its structure. The measured haptic torque was varied from 0.3 N·cm to 2.4 N·cm as the applied voltage increased from 0 V to 5 V. The performance of the proposed actuator was qualitatively evaluated by constructing virtual fishing environment where a user can feel not only the weight of a target object but also its motion.