Terahertz metamaterials on free-standing highly-flexible polyimide   substrates
  We have fabricated resonant terahertz metamaterials on free standing polyimide substrates. The low-loss polyimide substrates can be as thin as 5.5 micron yielding robust large-area metamaterials which are easily wrapped into cylinders with a radius of a few millimeters. Our results provide a path forward for creating multi-layer non-planar metamaterials at terahertz frequencies. 
H. Tao, A. C. Strikwerda, K. Fan, C.M. Bingham, W. J. Padilla, X.   Zhang, R. D. Averitt