Creating periodic local strain in monolayer graphene with nanopillars patterned by self-assembled block copolymer

A simple and viable method was developed to produce biaxial strain in monolayer graphene on an array of SiO₂ nanopillars. The array of SiO₂ nanopillars (1cm² in area, 80nm in height, and 40nm in pitch) was fabricated by employing self-assembled block copolymer through simple dry etching and deposition processes. According to high resolution micro-Raman spectroscopy and atomic force microscopy analyses, 0.9% of maximum biaxial tensile strain and 0.17% of averaged biaxial tensile strain in graphene were created. This technique provides a simple and viable method to form biaxial tensile strain in graphene and offers a practical platform for future studies in graphene strain engineering.