Haptic perception interaction effects between vibrotactile and compressive stimuli in wearable devices

Multi-haptic devices can simultaneously deliver different types of haptic feedback, allowing for an enhanced and richer user perception of the sensation delivered. Integrating different haptic actuation mechanisms in one device, however, can lead to interference and masking of individual sensations. This work investigates a modular, soft goods-based wearable multi-haptic device to study perceptual interference between simultaneous haptic stimuli. The garment-based haptic system featured both vibrotactile and shape memory alloy (SMA)-based compression stimuli that could be individually (or simultaneously) deployed to the wearer. We studied the perception thresholds for both individual and simultaneous sensation to evaluate the impact of simultaneous vibration on the resultant compression perception thresholds. The results show that the compression perception thresholds at the wrist were not significantly affected in the presence of vibration. Wearability factors such as sizing, and the material of the device, however, affected both the user experience and the functional performance of the device.