Wide-Bandwidth Soft Vibrotactile Interface Using Electrohydraulic Actuator for Haptic Steering Wheel Application

This letter presents a novel soft vibrotactile interface with a wide acceleration bandwidth that can be applied to a curved surface, such as a steering wheel. This haptic interface utilizes the surface charge-inducing characteristic of polyvinyl chloride (PVC) gel and adopts a design where hydraulic pressure is induced upon actuation. This working principle significantly increases the output force of the device, which enables a high-performance haptic interface. In addition, the small contact angle due to its curved shape was analyzed as an important parameter for high-frequency performance. Results showed that the proposed haptic interface can generate sufficient acceleration performance (>3 G) over a broad frequency range (90-700 Hz) with a maximum value near 6 G. Due to this high performance, user test participants could certainly feel the generated vibration with a sensation level of 22.5-44.8 dB from 10-360 Hz at 3 kV.