High precision electrostatic actuator with novel electrode design

A novel electrode design of electrostatic surface drives, which can reduce the drives' force ripple considerably, is described in this paper. Actuators with large travel and highly precise motion control are required for many micro mechanical systems. Electrostatic surface drives are promising, since their structures are very simple and they easily possess large travel. However, surface drives often have large force ripple that prevents precise motion control. To suppress the force ripple, we propose to utilize skew technique for their electrodes. The analytical results show that utilizing the new electrode design can reduce force ripple by 75%, without a remarkable lowering of thrust. Reducing force ripple leads to smooth slider motions, higher driving efficiency, more quietness, and higher controllability which is experimentally confirmed using a newly fabricated prototype drive.