  The presence of wrinkles in Graphene Nanoribbons (GNR) and other
two-dimensional (2D) materials significantly alter their mechanical,
electronic, optical properties, which can be either beneficial or detrimental.
Experimentally, it has been observed that during the commonly used growth
process of GNR, water molecules, sourced from ambient humidity, can be diffused
in between GNR and the substrate. The water diffusion causes wrinkle formation
in GNR, which influences its properties. Furthermore, the diffused water
eventually dries, creating the alteration not only in the geometry of Wrinkled
Graphene Nanoribbons (WGNR) but also its features. Computational analysis of
these phenomena can provide an atomistic-level understanding of the phenomena.
Therefore, in this work, Molecular Dynamics (MD) simulations are performed to
model the water diffusion and evaporation in between GNR and its substrate, and
their effect on wrinkle formation and dynamics. Additionally, Density
Functional Theory (DFT)-based analysis is used to characterize the difference
in the electronic structure of WGNR caused by the change in wrinkle geometry.
Our study reveals that the initially distributed wrinkles tend to coalesce to
form a localized wrinkle whose configuration depends on the initial wrinkle
geometry and the amount of diffused water. The wrinkle configuration changes
upon drying, while it remains static until the complete drying. The movement of
the localized wrinkle is the combination of three fundamental modes - bending,
buckling, and sliding. The stress analysis reveals that the maximum stress is
at the base of the wrinkle, and its magnitude is always below the plasticity
limit. The DFT results provide insight into the potential of using the wrinkles
to control the direction of electron flow for the applications in flexible
electronics.
