Fingertip Wearable High-resolution Electrohydraulic Interface for Multimodal Haptics.

Fingertips are one of the most sensitive regions of the human body and provide a means to dexterously interact with the physical world. To recreate this sense of physical touch in a virtual or augmented reality (VR/AR), high-resolution haptic interfaces that can render rich tactile information are needed. In this paper, we present a wearable electrohydraulic haptic interface that can produce high-fidelity multimodal haptic feedback at the fingertips. This novel hardware can generate high intensity fine tactile pressure (up to 34 kPa) as well as a wide range of vibrations (up to 700 Hz) through 16 individually controlled electrohydraulic bubble actuators. To achieve such a high intensity multimodal haptic feedback at such a high density (16 bubbles/${\mathrm{cm}}^{2}$) at the fingertip using an electrohydraulic haptic interface, we integrated a stretchable substrate with a novel dielectric film and developed a design architecture wherein the dielectric fluid is stored at the back of the fingertip. We physically characterize the static and dynamic behavior of the device. In addition, we conduct psychophysical characterization of the device through a set of user studies. This electrohydraulic interface demonstrates a new way to design and develop high-resolution multimodal haptic systems at the fingertips for AR/VR environments.