Moisture Transfer: A Perceptual Wetness Illusion Through Thermal and Wet Integration

Simulating wetness in interactive systems is challenging due to the lack of dedicated hygroreceptors in human skin and the complexity of delivering physical moisture. We introduce Moisture Transfer, a perceptual wetness illusion in which users feel moisture at a dry site when cold and wet stimuli are applied nearby. This illusion arises from the brain’s spatial integration of thermal and tactile cues, offering a new pathway to render wetness without direct contact. We investigate this illusion by establishing it with a single finger and show that thermal congruence enhances perceived wetness. We then explored its spatial extent across five fingers, revealing lateral transfer of wetness. Finally, we applied these findings to create a proof-of-concept VR interface that evokes full-hand wetness using minimal actuation. We conclude with design implications for XR and wearable systems and outline future work exploring body-wide wetness illusions and multisensory integration.