Etching- and Intermediate-free Graphene Dry Transfer onto Polymeric Thin Films with High Piezoresistive Gauge Factors

A facile exfoliation method utilizing van der Waals (vdW) interaction solely to transfer CVD grown monolayer graphene onto biaxially oriented nanoporous UHMWPE thin films is reported. The technique harnesses the enhanced vdW interactions developed at the graphene/polymer film interface as a result of selective partial melting of the polymer film. The surface of the graphene covered polymer film replicates topological features of the catalytic copper surface, and shows uniform large-area graphene coverage as characterized by 2D Raman mapping, SEM and AFM. The composite film exhibits a high surface conductivity and a piezoelectric gauge factor of up to 3100. This new transfer method paves the way for etching- and intermediate-free transfer for other 2D materials or nanostructures, in large areas and at ease.