Free-standing terahertz metamaterial fabricated via injection molding

Summary form only given. We demonstrate a technique of fabricating freestanding all-metal two-dimensional (2D) and three-dimensional (3D) terahertz metamaterials through injection molding of gallium, a metal that melts at temperatures slightly above room temperature. To obtain free-standing metamaterials, two polydimethylsiloxance (PDMS) molds are created using conventional soft lithography, reversibly bonded through van der Waals forces, and then peeled away after gallium is injected and solidified. We demonstrate three different approaches for creating 3D metamaterials: a multilayer stack, a manually folded structure and a directly injection molded 3D structure. The transmission properties of these devices are measured using terahertz time-domain spectroscopy.