Nanoscale Young's modulus and resistivity of flexible Au films on PET substrates revealed by atomic force microscopy

Flexibility is a critical factor in the design of electronic devices, and gold (Au) is widely used for flexible electrodes due to its excellent conductivity and moderate softness. This study investigates the nanoscale Young's modulus and resistivity of Au films with thicknesses ranging from 5 nm to 100 nm. Atomic force microscopy (AFM) was employed to characterize the mechanical properties and surface morphology of the films. Electrical resistance measurements were conducted under both flat and bent conditions to evaluate changes in conductivity due to mechanical strain. Our results indicate that Au films thinner than 10 nm fail to form a continuous conductive surface, hindering efficient current flow. In contrast, films thicker than 10 nm achieve reliable conductivity. Although conductivity decreases under bending, the films maintain sufficient performance for practical applications. These findings offer valuable insights into optimizing Au film thickness to balance flexibility and conductivity, enhancing the design of flexible electronic devices.