Existing research showed that unpleasant haptic feedback, such as pain, could enhance the user experience and performance in various scenarios (e.g. entertainment and training). This paper introduces ThermOuch, a wearable thermo-haptic device that leverages the thermal grill illusion (TGI) to simulate pain sensations in virtual reality (VR) without causing actual invasive/non-invasive harm. Our results of the user-perception experiments revealed that higher temperature-changing rates, particularly with increased warming, were associated with more intense pain perceived by the participants through our system. Furthermore, a higher ratio of warm-tocool temperature transitions reduced the sensation of coldness prior to pain. Our experiments also showed that introducing an additional stimulus unit potentially heightened pain perception, and altering the spacing between stimulus units modified the perceived pain area. Lastly, the user study in VR demonstrated that ThermOuch significantly enhanced the sense of presence and body ownership for the participants, as well as elevated their biosignal-indicated arousal levels.

Authors: Haichen Gao, Shaoyu Cai, Yuhong Wu, and Kening Zhu (*).