Mid-air haptic interfaces employ focused ultrasound waves to generate touchless haptic sensations on the skin. Prior studies have demonstrated the potential positive impact of mid-air haptic feedback on virtual experiences, enhancing aspects such as enjoyment, immersion, and sense of agency. As a highly immersive environment, Virtual Reality (VR) is being explored as a tool for stress management and relaxation in current research. However, the impact of incorporating mid-air haptic stimuli into relaxing experiences in VR has not been studied thus far. In this paper, for the first time, we design a mid-air haptic stimulation that is congruent with a relaxing scene in VR, and conduct a user study investigating the effectiveness of this experience. Our user study encompasses three different conditions: a control group with no relaxation intervention, a VR-only relaxation experience, and a VR+Haptics relaxation experience that includes the mid-air haptic feedback. While we did not find any significant differences between the conditions, a trend suggesting that the VR+Haptics condition might be associated with greater pleasure emerged, requiring further validation with a larger sample size. These initial findings set the foundation for future investigations into leveraging multimodal interventions in VR, utilising mid-air haptics to potentially enhance relaxation experiences.

翻译：空中触觉界面利用聚焦超声波在皮肤上产生非接触式触觉感知。已有研究表明，空中触觉反馈对虚拟体验具有潜在积极影响，可增强愉悦感、沉浸感和控制感等维度。作为高度沉浸式环境，虚拟现实（VR）正被当前研究探索为压力管理与放松工具。然而，将空中触觉刺激融入VR放松体验的影响迄今尚未被研究。本文首次设计与VR放松场景相一致的空中触觉刺激，并开展用户研究以验证该体验的有效性。我们的用户研究涵盖三种不同条件：无放松干预的对照组、仅VR放松体验组，以及包含空中触觉反馈的VR+触觉放松体验组。尽管未发现各条件间的显著差异，但初步趋势表明VR+触觉条件可能与更高愉悦感相关，需通过更大样本量进行验证。这些初步发现为未来探索利用空中触觉增强放松体验的多模态VR干预研究奠定了基础。