Monolayer MoS₂ Strained to 1.3% With a Microelectromechanical System

We report on a modified transfer technique for atomically thin materials integrated into microelectromechanical systems (MEMS) for studying strain physics and creating strain-based devices. Our method tolerates the non-planar structures and fragility of MEMS while still providing precise positioning and crack-free transfer of flakes. Furthermore, our method used the transfer polymer to anchor the 2D crystal to the MEMS, which reduces the fabrication time and increases the yield, and allowed us to exploit the strong mechanical coupling between the 2D crystal and polymer to strain the atomically thin system. We successfully strained single atomic layers of molybdenum disulfide (MoS ₂ ) with MEMS devices for the first time and achieved greater than 1.3% strain, marking a major milestone for incorporating 2D materials with MEMS. We used the established strain response of MoS ₂ Raman and photoluminescence spectra to deduce the strain in our crystals and provide a consistency check. We found good comparison between our experiment and the literature. [2018-0144]