Ultrasonic Mid-Air Haptics on the Face: Effects of Lateral Modulation Frequency and Amplitude on Users' Responses

Ultrasonic mid-air haptics (UMH) has emerged as a promising technology for facial haptic applications, offering the advantage of contactless and high-resolution feedback. Despite this, previous studies have fallen short in thoroughly investigating individuals’ responses to UMH on the face. To bridge this gap, this study compares UMH feedback on various facial sites using the lateral modulation (LM) method. This method allows us to explore the impact of two LM parameters -frequency and amplitude - on both perceptual (intensity) and emotional (valence and arousal) responses. With 24 participants, positive relationships between LM amplitude and perceived intensity and arousal were observed, and the effect of LM frequency varied across facial sites. These findings not only contribute to the development of design guidelines and potential applications for UMH on the face, but also provide insights aimed to enhance the effectiveness and overall user experience in haptic interactions across diverse facial sites.