A cantilever type of electrostatic vertical combdrive actuators may generate larger actuator displacement (typically over 70 um) with a relatively small and simple structure. The actuation voltage is lower while the actuation movement is robust without any typical sideway finger snapping phenomena due to a cantilever type of structure. Because of its small form factor, it can form a high fill factor array in applications such as lower power consumption display devices, sensitive electromagnetic radiation detector/detector arrays, etc. The MEMS (Micro-Electro-Mechanical Systems) electrostatic rotational actuators may have wide applications such as in optical shutter, optical chopper, optical switches, optical attenuators, optical tunable filter, RF shunt switch, RF ohmic contact switch, RF MEMS variable capacitors, MEMS display and sensitive electromagnetic radiation detector etc.