Electrostatic linear actuator developed as a biomimicking skeletal muscle (improvement in performance of the actuator by using liquid crystal as gap-filling medium)

We developed an electrostatic linear actuator for use as an artificial muscle which consists of parallel plate capacitors and a slider made of dielectric material. The most effective method to increase the output force of the actuator is optimizing the dielectric constant of the gap-filling medium, which fills the space between two electrodes of the capacitor, and increasing the dielectric strength of the medium for supplying high voltage to the capacitor. We chose liquid crystal as the gap-filling medium. Its maximum dielectric constant is 23 and the dielectric strength is 5.5 MV/m. The maximum output force of 56.5 mN was generated by the actuator filled with liquid crystal. This value is seven times as large as that generated by the same actuator filled with pure water used as the gap-filling medium in previous experiments.