Siyu Wang

Wearable haptic devices face a trade-off between providing rich feedback and preserving natural fingertip sensation. Current multi-DOF systems encumber the fingerpad, interfering with fingerpad sensory capabilities, while lightweight devices offer limited 1-DOF feedback. To address this, we present a 5.24 g, three-degree-of-freedom (3-DOF) haptic device that stimulates mechanoreceptors around the fingernail, leaving the fingerpad unobstructed. It uses two string-pulling motors for distal-proximal feedback and an arc-shaped pin motor for radial-ulnar stimulation to generate directional force vectors. This approach is grounded in the physiology of directionally-sensitive slowly adapting type 2 (SA2) mechanoreceptors. Experimental results demonstrate that the proposed 3-DOF approach improves weight and friction discrimination over single-DOF pressure feedback. Moreover, it delivers directional cues during static contact, a capability absent in vibrotactile systems, and achieves higher overall user satisfaction. By preserving fingertip sensation, the proposed device enables simultaneous interaction with virtual and physical objects, making it suitable for mixed reality applications.

Real-time simulation of large deformations in soft bodies has long faced a trade-off between computational efficiency and physical accuracy. This paper presents a novel Local Linear Corotated Finite Element Method that addresses this challenge through a hybrid strategy combining direct and iterative solvers. Our method decomposes the simulation domain into element groups; the dynamics within each group are resolved using a pre-computed direct method, while inter-group interactions are handled by efficient iterative constraints. This domain decomposition enables significant pre-computation, replacing runtime equation solving with fast matrix-vector multiplications. Experimental results demonstrate that the method achieves a better balance of speed and accuracy, demonstrating higher fidelity than similarly fast methods. The method supports anisotropic materials and achieves low volume change (2.95% error) under nearly incompressible conditions. Furthermore, its group-based architecture exhibits high scalability on multi-core processors, reducing computation time to 19.6 ms for a 120,000-tetrahedron model using 64 threads. These characteristics make our method well-suited for demanding applications such as surgical simulation, haptic feedback systems, and real-time digital twins, where both accuracy and performance are critical.

This study presents a lightweight, wearable fingertip haptic device that provides physics-based haptic feedback for dexterous manipulation in virtual environments without hindering real-world interactions. The device, designed with thin strings and actuators attached to the fingernails, ensures minimal weight (1.55 g per finger) and preserves finger flexibility. Integrating the software with a physics engine renders multiple types of haptic feedback (grip force, collision, and sliding vibration feedback). We evaluated the device's performance in pressure perception, slip feedback, typical dexterous manipulation tasks, and daily operations, and we gathered user experience through subjective assessments. Our results show that participants could perceive and respond to pressure and vibration feedback. Through dexterous manipulation experiments, we further demonstrated that these minimal haptic cues significantly improved virtual task efficiency, showcasing how lightweight haptic feedback can enhance manipulation performance without complex mechanisms. The device's ability to preserve tactile sensations and minimize hindrance to real-world operations is a key advantage over glove-type haptic devices. This research offers a potential solution for designing haptic interfaces that balance lightweight construction, haptic feedback for dexterous manipulation, and daily wearability.

This paper introduces a system that focuses on physics-based manipulation and haptic rendering to achieve realistic dexterous manipulation of virtual objects in VR environments. The system uses a coreless motor with wire as the haptic actuator and physics engine in the software to create a virtual hand that provides haptic feedback through multi-channel audio signals. The device simulates contact collision, pressure, and friction, including stick-slip, to provide users with a realistic and immersive experience. Our device is lightweight and does not interfere with real-world operations or the performance of vision-based hand-tracking technology.