Selective deposition of graphene sheets on a flexible substrate by a nonuniform electric field

This study reports on the precise positioning of high-quality graphene sheets on a flexible polyethylene naphthalate substrate using a dielectrophoretic (DEP) force. Positive DEP assembly is carried out using a 100 kHz frequency AC signal with a peak-to-peak voltage of 10 V. The presence and quality of the graphene flakes aligned around the prepatterned electrodes are characterized by scanning electron microscopy, optical microscopy, and micro-Raman spectroscopy. Current–voltage measurements were also used to evaluate the electrical properties of these flexible devices under varying compressive (−) and tensile (+) strain conditions up to ±0.6%, where the currents decreased with increasing strains.