Metal meshes are commonly used as reflective elements in far infrared astronomical instruments, where spectrally uniform reflectivity is important for stable Fabry–Perot interferometer performance and reliable calibration. In this work, we quantitatively compare the spectral reflectivity uniformity of representative metal mesh geometries using full wave electromagnetic simulations. Square and circular meshes with inductive and capacitive topologies are analyzed over the 200 to 400 GHz band. A figure of merit based on the normalized root mean square deviation of reflectance from a target value is used to evaluate spectral flatness. Parameter sweeps over lattice pitch and normalized feature size reveal well defined regions that minimize spectral variation. All four geometries can achieve comparable reflectivity uniformity when properly optimized, with square inductive meshes yielding the lowest figure of merit within the explored design space. The results provide practical guidance for selecting metal mesh geometries with flat reflectance profiles in far infrared Fabry–Perot interferometers and related optical systems.

Study of low Reynolds number flow environments are very practical in microfluidic systems, biological fluid scenarios, and micro underwater vehicles. Due to the influence of fluid viscosity, traditional propeller propulsion mechanisms completely fail in this environment. The spiral flagellar structure inspired by microorganisms can achieve stable propulsion in low Reynolds number fluids. However, the verification of its related theoretical models still lacks sufficient experimental support, and existing research mostly focuses on numerical theoretical derivation. Therefore, this article takes the mathematical model proposed by Lauga and Magariyama etc. of the spiral flagellar propulsion effect of micro robots in low Reynolds number fluids as the research object. Using both CFD simulation and real built robot to verify the model. The research results indicate that the result obtained from CFD simulation is highly consistent with the mathematical model proposed by Lauga and Magariyama. And the physical model further verified the rationality of the theoretical model. The research results can provide direct experimental basis for the design and optimization of biomimetic spiral flagellar propulsed robot in low Reynolds number environment.