BioHaptics: Emotion Modulation via Biosignal-Inspired Ultrasonic Mid-air Haptics in Video-Watching Experiences

Ultrasonic mid-air haptics (UMH) offers a novel way to modulate affective responses through contactless, biosignal features inspired haptics (i.e., BioHaptics). Yet, the effects of different BioHaptics on affective responses of emotions experienced during video-watching context are unclear, limiting the flexible emotion modulation and broader use of UMH as a natural affective design channel in enhancing everyday media consumption. This paper explores how BioHaptics encoded from different biosignal features (e.g., heart rate (HR), heart rate variability (HRV), and respiration amplitude (RA)) impact emotions in video-watching contexts. In two experiments with 70 participants, we assessed affective responses while adding three BioHaptics during the video-watching processes. Results showed that HR and RA haptics promoted RA and HRV, with potential increments in emotional pleasantness and regulation; HRV haptics lowered HR, leading to calmer responses. This research offers implications and recommendations for emotion modulation through UMH and advances the design of emotionally engaging multisensory feedback.