Stony Brook University The Graduate School

Doctoral Defense Announcement

Abstract

Numerical and Experimental Explorations on Load-bearing Kirigami Metamaterials and Structures

By

Imtiar Jalal Niloy

This dissertation focuses on the analysis of the mechanical behavior, deformation mechanisms, and load-bearing capabilities of kirigami metamaterials and structures through a combination of numerical and experimental methods. The technique of cutting and folding thin sheets – known as kirigami – has influenced the development of a class of metamaterials that use engineered cut patterns and geometries to produce shape transformations. With unique mechanical properties like tunable stiffness, flexibility, and bistability, these systems have potential uses in lightweight, deployable, and adaptive structures.

We begin by creating numerical workflows to study the mechanical behavior of bistable kirigami metamaterials. These models allow to predict and optimize the mechanical response, quantifying how geometry, cut patterns, boundary conditions and material properties affect stiffness, bistability, and actuation energy. We then perform experiments on metamaterial specimens characterized by distinct deformation mechanisms, to isolate key mechanical effects and to validate bistability and load-displacement behavior. Results are compared with simulations to assess accuracy and identify the effects of friction, viscoelasticity, and fabrication imperfections.


In the second part of the work, we extend the numerical-experimental workflow to non-periodic kirigami architectures, which we use to create load-bearing dome-like structures. Simulations and experimental tests show that geometric frustration and global buckling can transform planar Kirigami sheets into three-dimensional forms capable of supporting applied loads.


The final part of the study examines load bearing kirigami-based bulging tubes. Numerical simulations evaluate how programmed cut patterns enable controlled radial expansion under axial loading and allow the tubes to carry load while undergoing shape change. The performance of these kirigami structures is compared against more standard morphing structures.


The findings of this study advance the understanding of kirigami metamaterial mechanics and open new pathways for their implementation in structural, aerospace, and robotic applications.


Date: December 15, 2025 Program: Civil Engineering

Time: 11 am Dissertation Advisor: Paolo Celli

Place: 101 Charles B. Wang Center