FlexCube: A flexible multimodal haptic display

Abstract

As virtual technology rapidly advances globally, the integration of the sense of touch into virtual environments to enhance realism is becoming increasingly urgent, drawing significant attention from scientists and researchers. This has led to the development of innovative haptic devices designed to replicate tactile sensations, further immersing users in virtual experiences. However, despite significant research in this field, most of the current haptic devices appear to lack the ability to provide direct, flexible, and natural interactions. To address these challenges, this study introduces the FlexCube, a novel flexible multimodal haptic display capable of delivering three tactile sensations: softness, roughness, and temperature. The FlexCube is developed through the creation of two modules—a hydraulic-actuated module for temperature and contact area rendering and a roughness module using the electrovibration effect. Then, they are combined together and integrated with an available stiffness rendering device into one device - the complete FlexCube. Subsequent experiments were conducted to evaluate the performance and behavior of each module individually. The results demonstrate that the FlexCube is capable of rendering a step profile and real texture’s temperature profile, tracking a sinusoid contact area profile of 0.2 Hz with neglectable delay, and able to deliver salient roughness sensations with the maximum generated electrovibration force of 0.028N regardless of the possible surface deformation. Overall, the FlexCube can simultaneously deliver all the expected tactile sensations and appears to be a promising tool for applications in E-commerce, telepresence, and interactive simulations.