Three-phase electrostatic rotary stepper motor for skew angle compensation

We present a three-phase electrostatic rotary stepper micromotor for skew angle compensation of read/write heads in hard disk drives. The motor utilizes the electrical energy stored in the variable capacitances formed between the poles of a rotor and a stator. The rotor is suspended by a flexural suspension to avoid frictional contact during operation. The experimental characterization of a prototype having a diameter of 1.4 mm has demonstrated a rotational range of 26 degrees (±13 degrees) at 75 V and a maximum speed of 1.67 degree/ms.