A tunable terahertz metamaterial based on a micro-cantilever array

This paper reports a mechanically tunable terahertz metamaterial based on microscale electrostatic actuators. The device consists of an array of suspended cantilevers, forming LC resonators with underlying capacitive pads. The applied voltage can pull the cantilever downwards to increase the capacitance value in the resonator, and thus, redshift the resonant frequency. In our preliminary experiments, the resonant frequency can be tuned from 1.105 THz to 1.06 THz under a 40 V voltage; at the same time, the transmission amplitude can be modulated by approximately 15 dB at the resonant frequencies. The results enables the implementation of tunable terahertz devices, including modulators, polarizers and waveplates, employing conventional micro-electromechanical structures.