Seminar: Pave the Path for New Architectured Materials through Mechanics, Biomimetics, and 3D Printing

Abstract

Many natural material systems have evolved and adapted to optimize their functional performance by making efficient use of available resources via innovative architectures across all length scales. Inspired by these interesting architectures, new engineering solutions can be discovered and new materials with superior mechanical properties can be designed. As one part of this presentation, a new bio-inspired strategy for in-plane energy dissipation will be explored. This work was inspired by the seed coats of Portulaca oleracea, and Panicum miliaceum (common millet), which consist of stiff, planar cells (epidermis cells) articulated together via a network of wavy suture interface. Through an integrated approach of bio-inspired design and finite element (FE) simulations with direct mechanical experiments on their 3D printed multi-material structural analogues, the designs with sutural tessellation exhibit an unusual combination of mechanical properties including auxeticity and mutually amplified strength and toughness which can be systematically tuned by varying the waviness of the interface and material combination. The new concept shows a promising avenue of interdisciplinary research on developing new lightweight, damage-tolerant, functionally graded composites for protection, energy absorption and dissipation. As another part of the presentation, a new family of soft auxetic chiral mechanical metamaterials will be investigated. Due to chirality-induced internal rotation, this new category of architectured materials have unique deformation mechanisms and can preserve auxetic effect under large deformation. Also, it was discovered that the auxetic effects can be amplified via elevating internal rotation, and a novel sequential cell-opening mechanism can be achieved via innovative design. This new family of material can also significantly advance the micro-polar theory in in generalized continuum mechanics. These studies demonstrate a paradigm for weaving mechanics, biomimetic and 3D printing to prove and verify novel engineering concepts for designing the new generation of architecture materials with broad engineering and bio-medical applications.

About the speaker

Yaning Li received her PhD from the University of Michigan, Ann Arbor and post-doctoral training in mechanics, materials science, bio-inspired engineering and 3D printing from Massachusetts Institute of Technology. She is currently an assistant professor at the University of New Hampshire. Recently, she won an NSF/CAREER award to study the mechanics of a new family of auxetic chiral composites.

Hosted by Prof. Carlos Castro.