Vertically aligned carbon nanotube arrays as vertical comb structures for electrostatic torsional actuator

We have demonstrated an electrostatic torsional actuator with vertically aligned carbon nanotube (VACNT) arrays integrated on interdigitated vertical comb structures. The actuator was fabricated on a silicon-on-insulator wafer, and the VACNT arrays were synthesized selectively on conductive stator comb electrodes by thermal chemical vapor deposition process in order to create vertical height difference with respect to rotor comb electrodes. The VACNT-based vertical comb structures successfully induced electrostatic force for out-of-plane torsional motion of rotors. The fabricated devices with integrated VACNT arrays were robust and reliable throughout the long term operation tests up to 4.4 × 10 ⁷ cycles with an optical scan angle of 28.4° at a resonant frequency of 1.537 kHz, verifying the feasibility for practical applications.