This study introduces "Flip-Pelt," a motor-driven peltier device designed to provide rapid thermal stimulation and congruent pressure feedback in virtual reality (VR) environments. Our system incorporates eight motor-driven peltier elements, allowing for the flipping of preheated or cooled elements to the opposite side. In evaluating the Flip-Pelt device, we assess user ability to distinguish between heat/cold sources by their patterns and stiffness, and its impact on enhancing haptic experiences in VR content that involves contact with various thermal sources. Our findings demonstrate that rapid thermal stimulation and congruent pressure feedback provided by Flip-Pelt enhance the recognition accuracy of thermal patterns and the stiffness of virtual objects. These features also improve haptic experiences in VR scenarios through their temporal congruency between tactile and thermal stimuli. Additionally, we discuss the scalability of the Flip-Pelt system to other body parts by proposing design prototypes.

This study presents ErgoPulse, a system that integrates biomechanical simulation with electrical muscle stimulation (EMS) to provide kinesthetic force feedback to the lower-body in virtual reality (VR). ErgoPulse features two main parts: a biomechanical simulation part that calculates the lower-body joint torques to replicate forces from VR environments, and an EMS part that translates torques into muscle stimulations. In the first experiment, we assessed users’ ability to discern haptic force intensity and direction, and observed variations in perceived resolution based on force direction. The second experiment evaluated ErgoPulse’s ability to increase haptic force accuracy and user presence in both continuous and impulse force VR game environments. The experimental results showed that ErgoPulse’s biomechanical simulation increased the accuracy of force delivery compared to traditional EMS, enhancing the overall user presence. Furthermore, the interviews proposed improvements to the haptic experience by integrating additional stimuli such as temperature, skin stretch, and impact.

This study examines the feasibility of user-applied active locomotion in In-Car Virtual Reality (VR), overcoming the passivity in mobility of previous In-Car VR experiences where the virtual movement was synchronized with the real movement of the car. We present the concept of virtual steering gains to quantify the magnitude of user-applied redirection from the real car’s path. Through a user study where participants applied various levels of steering gains in an active virtual driving task, we assessed usability factors through measures of motion sickness, spatial presence, and overall acceptance. Results indicate a range of acceptable steering gains in which active locomotion improves spatial presence without significantly increasing motion sickness. Future works will attempt to further validate a steering gain threshold in which active locomotion in In-Car VR can be applicable.

Providing convincing proprioceptive cues is essential for immersive virtual reality (VR) navigation. However, this is challenging for seated users with restricted mobility. To address this gap, this study proposes LegSense, a method designed to induce the walking sensation in VR via electrical muscle stimulation (EMS). This method activates the leg muscle senses in sync with the gait cycle without requiring physical motion to enhance users' immersion. We evaluated the efficacy of LegSense through a user study and confirmed its potential in terms of walking sensation, embodiment, and presence compared to other static conditions (baseline and vibro-tactile). Additionally, participant interviews confirmed that LegSense effectively creates a leg movement illusion, suggesting its potential applications in diverse virtual scenarios to enhance VR experiences for seated users.