A Spherical Actuator-Based Hand-Held Haptic Device for Touch Screen Interaction

This paper presents a spherical actuator-based hand-held device that provides lateral force feedback for user interaction with the touch screen. The spherical actuator is built around a ball containing the magnetorheological elastomer (MRE). This design of the actuator not only allows it to move in multiple degrees of freedom but also realizes its direct interaction with the touch screen and enhances its lateral force feedback capability by utilizing the conductive and soft characteristics of the MRE. Meanwhile, using the magnetically conductive properties of the MRE, the lateral force can be controlled by current. In this paper, we introduced the overall structure of the device, described the fabrication of the MRE, and tested the relative permeability and surface friction properties of the MRE. Then, based on the structural parameters obtained by lateral force modeling and finite element analysis, we fabricated a prototype of the actuator and determined the lateral force control method through calibration tests. Finally, through physical measurements and psychophysical experiment, we comprehensively evaluated the lateral force performance of the actuator and its ability in displaying virtual surface friction. The experimental results confirm the effectiveness of the actuator in interacting with the touch screen and displaying the virtual surface friction characteristics.