An electrostatic linear actuator developed as a biomimicking muscle (Force generated by a two-dimensional integrated actuator)

We developed an electrostatic linear actuator for use as an artificial muscle that consists of parallel-plate capacitors and a slider made of dielectric material. We must integrate many unit actuators to generate a large output force. To integrate the unit actuator, we attempted to determine the optimal aspect ratio, i.e., distance between two electrodes of capacitor/length of electrode, which represents the integration rate of the actuator. It became clear through the computer simulation and the experimental measurement that the optimal range of the aspect ratio is from 1.6 to 1.7. We made a two-dimensional integrated actuator with twenty pairs of electrodes whose aspect ratio was 0.8. It was confirmed by the measurement of force that the experimental values agreed well with the corrected theoretical ones. The maximum output force of 42.3 [mN] was generated at the supply voltage of 200 [V].