Transparent Localized Haptics: Utilization of PVDF Actuators on Touch Displays

Abstract

Generating localized haptic feedback on touch displays has been a challenge in recent years. In this study, we introduce a haptic interface using transparent thin-film PVDF actuators to address this issue. The transparency feature can be used to mount the actuators at any location beneath the display, enabling localized haptic feedback as the generated vibration is primarily evident on the mounting area. Two different configurations are designed, simulated and prepared to explore the effectiveness of the proposed approach. The first configuration is used to characterize the haptic interface. Modal and forced-vibration analyses are performed to identify important design characteristics based on human factors. Subsequent 2AFC psychophysics experiments validate the characteristics. In the second configuration, eight actuators are attached to the touch surface in a 2 × 4 matrix formation and excited at different voltage amplitudes. Human experiments are conducted based on the results from corresponding forced-vibration analysis. The results show that subjects demonstrate an accuracy of 96% in identifying locations with haptic feedback when the actuators are excited with 232 Vpp. Overall, our study demonstrates the effectiveness of the proposed transparent haptic interface equipped with PVDF actuators in achieving localized haptic feedback on touch displays.

Lever Mechanism for Diaphragm-Type Vibrators to Enhance Vibrotactile Intensity

“…2A. In addition to other piezoceramics, such as lead titanate and quartz, synthetic polymers are also used as piezoelectric materials [22]- [24] instead of the ceramics we used, and behave as diaphragms when an alternating voltage is applied. The lever mechanism presented in this study can also be applied to such diaphragm-type vibrators.…”