This study introduces a cross-modal, tongue-involved interface designed to enrich taste and touch perception within Mixed Reality (MR) environments. It features a novel gear-like mechanism loaded with various flavored conductive jellies, forming a cross-modal platform. This interface enables the gear to present different flavor units to the user’s tongue, activated by specific virtual events. This setup fosters mutual communication and a playful experience between the physical and virtual worlds, leveraging the synesthesia of taste and tactile perceptions.

Impact events, which generate directional forces with extremely short impulse durations and large force magnitudes, are prevalent in both virtual reality (VR) games and real-world experiences. However, despite recent advancement in ungrounded force feedback technologies, such as air jet propulsion and propellers, these technologies remain 5-100x weaker and 10-500x slower compared to real-world impact events. For instance, they can only achieve 4N with a minimal duration of 50-500ms compared to the 20-400N forces generated within 1-5ms for baseball, ping-pong, drumming, and tennis. To overcome these limitations, we present AirCharge, a novel haptic device that accumulates air propulsion momentum to generate instantaneous, directional impact forces. By mounting compressed air jets on rotating swingarms, AirCharge can amplify impact force magnitude by more than 10x while matching real-world impulse duration of 3ms. To support high-frequency impacts, we explored and evaluated a series of device designs, culminating in a novel reciprocating dual-swingarm design that leverages a reversing bevel gearbox to eliminate gyro effects and to achieve impact feedback of up to 10Hz. User experience evaluation (n = 16) showed that AirCharge significantly enhanced realism and is preferred by participants compared to air jets without the charging mechanism.

Teleportation, which instantly moves users from their current location to the target location, has become the most popular locomotion technique in VR games. It enables fast navigation with reduced VR sickness but results in significantly reduced immersion. We present HeadWind, a novel approach to improve the experience of teleportation by simulating the haptic sensation of air drag when rapidly moving through the air in real life. Specifically, HeadWind modulates bursts of compressed air to the face and uses multiple nozzles to provide directional cues. To design the wearable device and to model airflow speed and duration for teleportation, we conducted three formative studies and a design session. User experience evaluation with 24 participants showed that HeadWind significantly improved realism, immersion, and enjoyment of teleportation in VR (p<.01) with large effect sizes (r>0.5), and was preferred by 96% of participants.

JetController is a novel haptic technology capable of supporting high-speed and persistent 3-DoF ungrounded force feedback. It uses high-speed pneumatic solenoid valves to modulate compressed air to achieve 20-50Hz of full impulses at 4.0-1.0N, and combines multiple air propulsion jets to generate 3-DoF force feedback. Compared to propeller-based approaches, JetController supports 10-30 times faster impulse frequency, and its handheld device is significantly lighter and more compact. JetController supports a wide range of haptic events in games and VR experiences, from firing automatic weapons in games like Halo (15Hz) to slicing fruits in Fruit Ninja (up to 45Hz). To evaluate JetController, we integrated our prototype with two popular VR games, Half-life: Alyx and Beat Saber, to support a variety of 3D interactions. Study results showed that JetController significantly improved realism, enjoyment, and overall experience compared to commercial vibrating controllers, and was preferred by most participants.