Low-Friction, High-Speed Rotary 3-Phase Micromotor Using the PolyMUMPS Process

We present the design and fabrication of an electrostatic side-drive micromotor that achieves the fastest operating speed reported for a device fabricated using the PolyMUMPS process. High-speed is obtained by optimizing the geometric parameters of the rotor and the stator electrodes, employing techniques to reduce friction in various regions of the micromotor and adopting multiple approaches to enhance the driving torque of the micromotor. The key geometrical parameters of the micromotor are determined through analytical modelling, bypassing intensive computational methods. The rotor diameter of the micromotor is 600 μm and has only 12 circular bearing supports each having radius of 3 μm. The rotary micromotor exhibits a speed of up to 7,875 rpm.