Affective Stroking: Design Thermal Mid-Air Tactile for Assisting People in Stress Regulation

Haptics for stress regulation is well developed these years. Using vibrotactile to present biofeedback, guiding breathing or heartbeat regulation is a dominant technical approach. However, designing computer-mediated affective touch for stress regulation is also a promising way and has not been fully explored. In this paper, a haptic device was developed to test whether the computer-mediated affective stroking on the forearm could help to assist people in reducing stress. In our method, we used mid-air technology to generate subtle pressure force by blowing air and generating thermal feedback by using Peltier elements simultaneously. Firstly, we found intensity and velocity parameters to present comfort and pleasant stroking sensations. Afterward, an experiment was conducted to find out whether this approach could help people mediate their perceived and physiological stress. A total of 49 participants were randomly assigned to either a Stroking Group (SG) or a Control Group (CG). Results showed that participants from SG felt more relaxed than those from CG. The physiological stress index, RMSSD, increased and LF/HF decreased in SG although these changes were not statistically significant. Our exploration created subtle, non-invasive, noiseless haptic sensations. It could be a promising alternative for assisting people in stress regulation. Design implications and future applicable scenarios were discussed.