Experimental Evaluation on the Effect of Electrode Configuration in Electrostatic Actuators for Increasing Vibrotactile Feedback Intensity

Vibrotactile feedback is a key feature of many modern touch displays, which greatly enhances user experiences when interacting with an onscreen interface. Despite its popularity in small touch screen devices, this haptic feature is absent in most large displays due to a lack of suitable actuators for such applications. Thus, a growing need exists for haptic actuators capable of producing sufficient vibrations in large touch displays. This study proposes and evaluates a novel electrostatic resonant actuator (ERA) with a moving mass and dual electrodes for increased vibration feedback intensity. The dual-electrode ERA was fabricated along with a comparable single-electrode ERA to investigate the effect of the electrode configuration on the maximum vibration intensity. When measured directly on the mass, the maximum vibration intensity of the dual-electrode actuator increased by 73% compared to the single-electrode actuator. When mounted and measured on a mock panel, the maximum vibration intensity of the dual-electrode actuator increased by nearly 65% compared to a similarly mounted single-electrode actuator. These results show that the dual-electrode configuration can significantly increase the vibration intensity when compared to the conventional ERA. This demonstrates a promising potential for the use of the proposed actuator for generating vibrotactile feedback in large touch displays.