Pneumatic unit cell arrays for tactile displays

This work presents a compact fingertip-sized 3 × 3 array of Pneumatic Unit Cell (PUC) actuators capable of delivering both static pressure and vibrotactile stimuli for tactile display applications. Two psychophysical studies were conducted to evaluate the perceptual rendering capabilities of the array, one in an uncontrolled environment setting and another in a controlled environment. The first study explored multi-stimulus pattern perception using varying numbers of active actuators and layout resembling lines and dots. Results showed that most patterns were perceived as discrete dots. The second study investigated the PUC array’s potential as a single-cell refreshable Braille display. High localization accuracy was observed for static pressure stimuli, with average proportional accuracy reaching up to 93%. Notably, transition methods and the number of actuator state changes did not significantly affect localization performance. These findings underscore the promise of PUC arrays for enabling compact tactile displays, provide insights for future multi-stimulus rendering, and demonstrate their potential as a single-cell unit in Braille systems.