Printing flexible terahertz metasurface of optical transparency

The paper reports an optical transparent metasurface and printing method. The double spiral symmetric structure of the metasurface is insensitive to the angle of incident terahertz or microwave, especially suitable for flexible and non-planar components. The printing method combines electroplating of nickel mold and printing of silver nanoparticle ink. Using the method, the spiral structure can be fabricated on ultrathin, flexible, and transparent substrates to achieve visible light transparency. For verification, a flexible metasurface filter with thickness of 200 μm and area of 120  ×  120 mm², which works in terahertz frequency range, is designed and printed. The transmission spectra under different bending conditions are measured and the results are consistent with the expectations. (paper)