Theoretical analysis of an electrostatic linear actuator developed as a biomimicking skeletal muscle

Recently Yano proposed a new theory of muscle contraction, termed the electrostatic linear actuator model. Based on this theory, we developed an electrostatic linear actuator as a biomimicking skeletal muscle. The fundamental actuator unit consists of a parallel plate capacitor and a slider made of dielectric material. Based on this model, we derived the theoretical formula for the thrust of the actuator. This formula revealed the following facts. The thrust can be maintained constant when the supply voltage is kept constant, and can be markedly increased by optimizing the dielectric constant of the fluid which fills the space of the capacitor. Using this formula, we designed a simple practical model expected to generate a thrust of 10 mN with the stroke of 10 mm. The surface area of this actuator was 1 cm².