Session: 13-15-01: Mechanics of Soft Materials I

Paper Number: 172221

Extreme Nonlinearity by Layered Materials Through Inverse Design 

Extreme mechanical properties in biological materials, such as seashell nacre, can be attributed to their multi-layer microstructures. These layers often interact among themselves collaboratively to achieve superior performance beyond the capacity of a single layer.

Here, inspired by these layered architectures in biological systems, we architect materials with layers of freeform microstructures to achieve precisely programmable and extreme nonlinear responses, such as multi-stage snap buckling and plateau responses. An inverse design paradigm is created to simultaneously optimize the local microstructure within each layer and the position of rigid pins interconnecting different layers, enabling intricate layer interactions within these architected materials. These variables are then used to characterize the mechanical responses defined by the stored-energy density functions through a tailored interpolation technique. The synergistic interactions among different layers collectively achieve unprecedented programmability over the desired extreme nonlinear responses. The unique multi-layer interaction of the layered architected material enhances the design flexibility, enabling responses that are difficult, if at all possible, to achieve with single-layer material architecture

We conduct a comprehensive study combining high-fidelity simulations, hybrid fabrication, and tailored experimental protocols to create layered architected materials, demonstrating their potential applications in energy dissipation and absorption, wearable devices, and information encoding. We explore the versatile potential of snap-buckling responses in layered architected materials, which have evolved from critical mechanical instabilities to valuable mechanisms for advanced applications. Snap-buckling materials dissipate energy efficiently during deformation, transitioning between stable states while maintaining resilience through repeated cycles demonstrated in the created materials. These properties make them ideal for damping systems, such as vibration isolators, and biomedical wearable devices like tremor mitigation systems. Their tunable, adaptive behavior also can be applied to soft wearables, such as joint-specific and patient-specific support, with structures offering controlled stiffness and tactile sensing. Additionally, we investigate the programmable single- and multi-stage plateau responses, which can transfer external energy into stored energy. This feature benefits wearable devices and energy-absorbing systems, such as fall protection belts that reduce impact forces and car bumpers with multi-stage plateau responses that improve safety for both pedestrians and occupants by adapting to collision severity. Leveraging the feature of multi-stage snap buckling, we manipulate the snapping sequence and effectively encode and store information within the architected material, unlocking possibilities for data encryption. With the rapid advancement of architected mechanical materials, we present a pathway to engineer future programmable materials, characterized by their layered architecture and remarkable ability to achieve precise and extreme nonlinear responses.

We envision these layered architected materials, capable of achieving extreme nonlinear responses, hold substantial promise for transformative advancements across diverse fields, including vibration control, wearables, and information encryption.

Presenting Author: Xiaojia Shelly Zhang University of Illinois Urbana-Champaign

Presenting Author Biography: Dr. Xiaojia Shelly Zhang is a David C. Crawford Faculty Scholar and Associate Professor at the Department of Civil and Environmental Engineering at the University of Illinois at Urbana Champaign (UIUC). She directs the MISSION (MuIti-functional Structures and Systems desIgn OptimizatioN) Laboratory. Dr. Zhang holds B.S. and M.S. degrees from UIUC and a Ph.D. degree from Georgia Tech. Her research explores topology optimization, inverse design, 3D/4D printing, and data-driven models to develop multi-functional, sustainable, and resilient materials, structures, and robots for applications at different scales. She is the recipient of the National Science Foundation CAREER Award, the ASME Journal of Applied Mechanics Award, the DARPA Young Faculty Award, the AFOSR Young Investigator Award, the Leonardo da Vinci Award from ASCE, Dean’s Award for Excellence in Research, Dean’s Award for Early Innovation, the DARPA Director's Fellowship, the Thomas J.R. Hughes Young Investigator Award from ASME, UIUC Campus Distinguished Promotion Award, the Henry Hess Early Career Publication Award from ASME, the Haftka Young Investigator Award from International Society for Structural and Multidisciplinary Optimization (ISSMO). Dr. Zhang serves on the Executive Committee of the International Society of Structural and Multidisciplinary Optimization (ISSMO) and is a Review Editor for the Journal of Structural and Multidisciplinary Optimization and an Associate Editor for the Journal of Applied Mechanics.

Authors:

Xiaojia Shelly Zhang University of Illinois Urbana-Champaign
Zhi Zhao University of Illinois Urbana-Champaign
Rahul Kundu University of Illinois Urbana-Champaign
Ole Sigmund Technical University of Denmark