DMREF/Collaborative Research: Graphene Based Origami and Kirigami Metamaterials

University Of California-Santa Barbara, Santa Barbara CA

Investigators

Abstract

Graphene-Based Origami and Kirigami Metamaterials Non-Technical Description: The paper arts of origami and kirigami ('ori' = fold, 'kiri' = cut) provide a powerful framework to design responsive and tunable new materials. For example, a simple series of cuts can turn a sheet of paper into an accordion-like spring, or a sequence of folds can convert it into a swan. Indeed, many biological tissues develop folds and cuts reminiscent of origami and kirigami that endow them with distinct and useful mechanical properties. The seemingly limitless number of forms that can be created speaks to the potential of exploiting such design principles for materials beyond paper. This project will extend these design ideas to the microscale using graphene, an atomically thin two dimensional material, as the nanoscale paper foundation. Lithographic techniques borrowed from the semiconductor industry will be used to pattern the graphene, and a variety of approaches will be employed to create folds, all chosen to realize a specific mechanical property. The focus is on creating mechanical 'metamaterials' - materials whose properties reflect the patterns of folds and cuts rather than the properties of the underlying paper. With room temperature applications in mind, the theoretical effort will focus on the crucial role of thermally-activated Brownian motion in determining the material properties of graphene monolayers with cuts and folds. This paper-arts-inspired strategy has the potential to fundamentally transform the way materials are designed for the micro-world and could find applications in areas ranging from micro-robotics to mechanical sensors and actuators that mimic biologically 'active' tissues. Technical Description: Using lithographic techniques, graphene sheets will be perforated and cut to create modules with prescribed mechanical properties. These modules will be assembled to create mechanical meta-materials whose response to applied stresses, temperature, and other environmental signals can be tailored. The project focuses on the following interrelated goals: (a) Experimentally testing current predictions for graphene's thermomechanical properties and their dependence on geometry and boundary conditions; (b) Creating a library of mechanically programmable modular units out of cut graphene sheets; (c) Designing meta-materials assembled out of the basic graphene kirigami and origami modules to achieve a particular function; (d) Creating a theory of thermally excited atomically thin membranes with cuts and folds, to guide experiments and improve understanding of the basic principles. These goals will form the cornerstone for building a general-purpose open source design tool that can be used by engineers to assemble materials out of the origami and kirigami based modules, simulate their mechanical properties, and allow for iterative design work flows. This tool will be used to promote rapid materials discovery, development, and property optimization of atomic membrane origami and kirigami metamaterials.