MEAM Ph.D. Thesis Defense: “Exploring Self-Assembly of 2D Materials: Insights from Graphene Auto-Kirigami”

In nature, thin sheets bend, fold, and curve to create functional three-dimensional forms—from insect wings to leaves and flower petals. Over the past decades, such behavior has inspired engineered systems ranging from soft robotics to deployable electronics. Extending these ideas to atomically thin two-dimensional (2D) materials such as graphene opens new opportunities: these materials can transform into structures that extend beyond flat geometry through self-driven processes. Graphene, for example, can spontaneously assemble into self-stacked structures through self-folding, self-tearing, and nearly frictionless self-propagation, all driven by interfacial energy. We introduce the term auto-kirigami (AK) to describe these self-folded and self-propagating structures, in analogy to kirigami—the cutting and folding of thin sheets to create complex morphologies, highlighting the spontaneous nature of this process.

AK represents a unique form of self-assembly in 2D materials with implications spanning function, fabrication, and fundamental understanding. Yet, key questions remain regarding how AK initiates and grows, and how it varies across material systems. In particular, the mechanisms that control its onset, directionality, and resulting morphology remain unresolved. In this talk, I will present a comprehensive investigation of AK formation that integrates experiments, continuum modeling, and molecular dynamics simulations. I will show how tip-induced shear in graphene enables reproducible AK formation, how lattice-level anisotropies govern its directional growth and geometry, and how atomistic simulations reveal the initiation pathways inaccessible to experiments. These results provide a unified understanding of AK as a self-driven phenomenon and highlight its potential as a programmable route to reconfigurable nanoscale architecture.