Abstract
A 2-DOF robotic arm using electrostatic film actuators has been developed. The electrostatic actuator consists of slider and stator films that are made of polyimide FPC (flexible printed circuit) films in which three-phase parallel electrodes with a width of 100μm are embedded at regular intervals of 200μm. The electrostatic actuator has unique characteristics, such as lightweight, high-power, and flexible. Besides, it can directly generate large force without reduction gears. In this paper, we discuss utilization of the electrostatic actuator for consumer robots, and develop a prototype robotic arm. The robotic arm consists of an upper arm and a forearm both with the electrostatic actuators, but in different configurations. In the upper arm, flexible electrostatic actuator is situated in bent state along inside wall of the arm. This arrangement enables putting a large actuator in a narrow space. In the forearm, a pair of actuators constructs antagonistic muscle-like structure to reduce the total weight of the arm. The upper arm actuator and forearm actuator generates joint torque of 34.5N·cm and 9N·cm, respectively. Step responses of the robotic arm in a position feedback system are measured. Finally, direct teaching and playback of a pick-and-place task was performed utilizing fine back-drivability of the robotic arm.
