13:00 〜 13:15
▲ [17p-A305-1] [The 53rd Young Scientist Presentation Award Speech] A reconfigurable H-shaped THz metamaterial based on an ultra-small micromechanical cantilever array
キーワード：Metamaterials, THz waves, MEMS
To develop terahertz (THz) technologies used for upcoming applications such as communications beyond 6G, active manipulations for THz waves are researched by integrating reconfigurable metamaterials (MMs) and microelectromechanical systems (MEMS). However, only a slow tuning speed of tens kHz has been realized due to a limited mechanical resonant frequency fmr caused by a large size of MEMS actuators. In this work, an H-shaped MM (H-MM) integrating with ultra-small MEMS cantilever actuators was numerically and experimentally proposed. The measured fmr was further increased to reach over 500 kHz by the use of a wall structure. The device can serve as an ultrafast active shutter for THz waves.
The proposed MEMS-driven H-MM consists of a quartz substrate, leads for applying the drive voltage embedded under a SiO2 isolation film, a planar gold H-MM formed on the surface layer, and a MEMS cantilever array formed to align the split bar of the H-MM. The H-MM is electrostatically reshaped by the deformation of cantilevers from suspended (off-state) to pulled in (on-state), thereby changing the transmission response for THz incidences. The device was fabricated by using a surface micromachining technique.
The optical response of the device was measured via a THz time-domain spectrometer. A contrast of 55% in transmittance spectra at 0.61 THz was offered by static off- and on-state devices due to the different optical resonant frequencies at the two states. The mechanical response of the cantilever was measured via a Polytec MSA-400 microsystem analyzer. By optimizing the structure of the cantilever, the measured fmr was increased by 1.25 times to reach 530 kHz.
The proposed MEMS-driven H-MM consists of a quartz substrate, leads for applying the drive voltage embedded under a SiO2 isolation film, a planar gold H-MM formed on the surface layer, and a MEMS cantilever array formed to align the split bar of the H-MM. The H-MM is electrostatically reshaped by the deformation of cantilevers from suspended (off-state) to pulled in (on-state), thereby changing the transmission response for THz incidences. The device was fabricated by using a surface micromachining technique.
The optical response of the device was measured via a THz time-domain spectrometer. A contrast of 55% in transmittance spectra at 0.61 THz was offered by static off- and on-state devices due to the different optical resonant frequencies at the two states. The mechanical response of the cantilever was measured via a Polytec MSA-400 microsystem analyzer. By optimizing the structure of the cantilever, the measured fmr was increased by 1.25 times to reach 530 kHz.