“Pattern and Peel” method for fabricating mechanically tunable terahertz metasurface on an elastomeric substrate

In this article, we explore a mechanically tunable metasurface on an elastic polydimethylsiloxane (PDMS) membrane operating at Terahertz (THz) frequencies synthesized using a “pattern and peel fabrication” technique. The tunability of the metasurface is based on the change of physical dimensions of the individual micro-structures due to the strain caused by mechanical stretching. The novelty of this technique is the ability to use high resolution e-beam patterning in contrast to established screen-printing techniques reported in the literature. The metasurface studied in this article is a periodic lattice of split-ring structures resonant at THz frequencies. The effect of mechanical stretching on the response of the metasurface is investigated thoroughly through experiments and numerical simulations. The response of the metamaterial to stretching manifests as a shift in the higher order mode by ∼ 12% for an applied strain of ∼ 25%. This tunability of the spectral response with macroscopic strain is not only substantial for the given structure, but also follows a linear behavior. This device can have potential applications in communications technology, remote strain sensing, chemical and biological sensing.