Research on a Stiffness Pre-programmable Flexible Actuator Based on Electrostatic Hydraulics

Flexible actuators possess significant application value in fields such as bionic robots and human-computer interaction due to their excellent flexibility and environmental adaptability. Electrostatic hydraulic actuation technology integrates the advantages of dielectric elastomers and hydraulic actuation, serving as an ideal approach for flexible bionic actuation. Its performance is closely associated with the deformation characteristics of the liquid bag, and flexible film modification is a key means to regulate the mechanical properties of the liquid bag. Existing studies mainly focus on the effects of electrode structures and dielectric liquid properties on actuators, while systematic and quantitative research on the thickness of flexible films - a core parameter - remains insufficient. In this study, an electrostatically driven hydraulic actuator was fabricated. It achieves precise control of microdisplacement through an electrostatic field and realizes large-stroke and high-output-force actuation by combining the incompressibility and force amplification characteristics of the hydraulic medium. By adjusting the thickness of the flexible film, the effects on the film's own mechanical properties, electric field force transmission efficiency, and liquid bag deformation law were systematically investigated, and the correlation mechanism between thickness and liquid bag deformation characteristics was quantitatively analyzed.