Haptic stylus with inertial and vibro-tactile feedback

In this paper, we introduce a novel stylus capable of displaying two haptic effects to the user. The first effect is a tactile flow effect up and down along the pen, and the other is a rotation effect about the long axis of the pen. The flow effect is based on the haptic illusion of “apparent tactile motion”, while the rotation effect comes from the reaction torque created by an electric motor placed along the stylus shaft. The stylus is embedded with two vibration actuators at the ends, and a DC motor with a rotating balanced mass in the middle. We show that, it is possible to create flow and rotation effects on the stylus by driving the actuators on the stylus. Furthermore, we show that the timing and the actuation patterns of the vibration actuators and DC motor on the stylus significantly affect the discernibility of the synthesized perceptions; hence these parameters should be selected carefully. Two psychophysical experiments, each performed with 10 subjects, shed light on the discernability of the two haptic effects as a function of various actuation parameters. Our results show that, with carefully selected parameters, the subjects can successfully identify the flow of motion and the direction of rotation with high accuracies.