MEMS-Based Dual-Frequency Metasurface for Full-Space Terahertz Wavefront Control

Terahertz (THz) waves have significant potential in imaging, sensing, and high-speed wireless communication due to their unique spectral properties. However, precise and reconfigurable wavefront control remains difficult due to material losses and fabrication constraints. Micro-Electro-Mechanical Systems (MEMS)-integrated metasurfaces provide an effective approach by enabling dynamic mechanical tunability at subwavelength scales. Most existing MEMS-based metasurfaces operate at a single frequency and regulate either transmission or reflection, which limits their functionality in multifunctional applications. This work introduces a MEMS-actuated terahertz metasurface that achieves high-efficiency transmission and reflection at dual-frequency of 0.315 THz and 0.42 THz. Independent control of two MEMS actuators enables a tunable phase encoding mechanism, offering programmable wavefront manipulation. The results confirm distinct phase responses with high performance, demonstrating the potential of MEMS-integrated metasurfaces for adaptive THz beamforming and secure wireless communication.