A plate tuning fork shaped tactile display using elastic waves

Through the present study, the tactile display for representing surface roughness by using a Langevin-type piezoelectric ultrasonic transducer is developed. We draw reference from the tuning fork and the ancient Chinese Chime-bell in order to enhance the vibration amplitude and make the modal figures of the device adequately complex. A U-shape aluminum plate is utilized as the touch interface on which several rib-type grooves are processed. A bolt clamped Langevin-type piezoelectric ultrasonic transducer is jointed to the bottom of the fork plate. Two sets of piezoelectric elements are adopted to excite the different modes respectively. The FEM analysis shows that a large number of vibration modes with near frequency are produced on the U-shape plate. Then a set of preliminary experiments on sensory evaluation is carried out to confirm that the output stimulations with fingertip´s movement are effective to realize an artificial roughness tactile sensation.