Tensile Mechanical Properties and Edge Defect-Driven Degradation in Bilayer Graphene

Bilayer graphene attracts significant attention due to
its unique
electronic structure and excellent physical properties, with its mechanical
performance being crucial for understanding deformation mechanisms
and assessing application reliability. The mechanical properties of
bilayer graphene measured by atomic force microscopy currently exhibit
considerable scatter and show clear deviations from theoretical predictions.
In situ tensile testing is widely regarded as a more reliable and
authoritative approach for evaluating the mechanical properties of
two-dimensional materials. Accordingly, the Young’s modulus
of bilayer graphene is measured to be 873.80 ± 12.68 GPa using
a push-to-pull device inside a scanning electron microscope, which
is close to the theoretical value. Moreover, the integration of bilayer
graphene into device architectures requires micro/nanoscale patterning
and shaping, which inevitably introduces edge defects. However, it
remains experimentally challenging to precisely control the concentration
of these edge defects. To address these limitations, a combined approach
of molecular dynamics simulations and machine learning was employed
to systematically uncover the effects of edge defects on the mechanical
behavior of bilayer graphene. This study provides a theoretical foundation
for a deeper understanding and optimization of the mechanical behavior
of bilayer graphene, thereby laying important groundwork for its application
in microelectronic devices.