Tri-Modal Tactile Display and Its Application Into Tactile Perception of Visualized Surfaces

Tactile representation on touchscreens plays an important role in improving realism and richness of users' interaction experience. The dynamic lateral force range and the efficient feedback dimensions are very critical in determining the fidelity of tactile displays. This article develops a tri-modal Electrovibration, Ultrasonic Vibration, and Mechanical Vibration (EUMV) tactile display integrating three types of representative principles, which enhances the dynamic lateral force range by leveraging electrostatic and ultrasonic vibrations stimuli, and induces the normal feedback dimension by utilizing mechanical vibration stimulus. Then, a tactile perception scheme with the EUMV display is proposed for simultaneously rendering contour and texture roughness features of visualized surfaces, in which the contour gradient-lateral force model and the texture gradient-perceived roughness model are determined respectively. Objective and subjective evaluations with 20 participants show that the novel scheme establishes significant improvements in both correct recognition ratios of geometric shapes and tactile perception realism of visualized images than the previous studies.