Abstract
Despite advances in vibrotactile displays, most existing systems are limited in their ability to deliver calibrated, frequency-differentiated stimulation across multiple touch modes. This constrains our understanding of how supra-threshold frequency modulation influences tactile perception, particularly in dynamic, shape-based interactions. To address this gap, we introduce the PinArray-a novel hybrid haptic device featuring a 4 × 3 array of independently actuated pins capable of delivering vibrations from 0 to 300 Hz. The PinArray uniquely supports static, passive, and active touch conditions, enabling nuanced exploration of tactile shape encoding. We evaluated the device in a user study examining the perception of edge-like shapes generated via frequency pairings. Results show that specific combinations, especially those involving static and dynamic frequency pairs, significantly enhance shape recognition. These findings highlight the device's potential for advancing both perceptual research and the development of expressive tactile interfaces.