Towards pressure-based feedback for non-stressful tactile notifications

Smartphones, wearables, and other mobile devices often use tactile feedback for notifying users. This feedback type proved to be beneficial since it does not occupy the visual or auditory channel. However, it still can be distracting in other situations such as when users are already stressed. To investigate tactile feedback patterns which do not increase the user's stress level, we developed two wrist-worn prototypes capable of providing tactile feedback (i.e., vibrotactile and pressure-based feedback). Further, we conducted a user-study with 14 participants comparing both feedback types. The results suggest that vibrotactile feedback increases the user's stress level more, compared to pressure-based feedback particularly applied when the user currently has a low stress level. Consequently, we present implications for designing notifications for mobile and wearable devices.