Award
2020 NSF CAREER Award Winner
Department
Department of Mechanical Engineering
Awarded Project
Biomineralized architected metamaterials: structural design and formation mechanisms
Biominerals, like teeth, bone, and seashells, are mineral-based structures formed by organisms. They possess complex 3D morphologies, and the internal microscopic structures of many biomineral-based structures are extremely intricate and carefully organized in 3D as well. This hierarchical structural complexity leads to biomineralized structures’ remarkable mechanical strength and durability, despite the fact that the minerals themselves are intrinsically brittle.
Ling Li aims to characterize the complex 3D microstructure and underlying formation mechanisms of biominerals in echinoderms, such as ossicles found in the skeleton of a starfish. Ossicles are characterized by their lattice-like porous microstructure based on the single-crystalline calcite, which makes them lightweight, strong, and damage tolerant. Li believes that insights on the multi-scale structure, formation mechanisms, and mechanical properties obtained in this study will provide important lessons for the design and fabrication of synthetic, low-density materials and benefit the U.S. economy and society.
What path did you take to get to this point in your research and career?
I became really interested in research during my undergraduate research program at National University of Singapore, when I was working on the synthesis and self-assembly of nanomaterials. Also during this period of time, I started to appreciate that some of the most complex and versatile materials are produced by nature.
This later drove me to systematically study biological structural materials during my Ph.D. and postdoc studies at MIT and Harvard. I joined Virginia Tech as an assistant professor in 2017 and established the Laboratory of Biological and Bio-inspired Materials. Now together with postdocs and undergraduate and graduate students, our group here at the Department of Mechanical Engineering works hard to address both scientific and engineering challenges in developing novel materials by using the bio-inspired approach. Along this path, I feel really grateful that I am always supported by my family, advisors, colleagues, and students.
What impact do you hope your research will have?
The impact of my research in general is twofold. First, my research aims to push the boundaries of our scientific understanding of biological materials in terms of their structures, formation, properties, and functions. Our current knowledge on how organisms design and produce their hard tissues or skeletons is rather limited. For example, why our teeth and mollusk shells are so strong and resistant to damage and wear although the minerals themselves inside are very brittle and easy to fracture.
Additionally, a fundamental understanding of the formation-structure-property relationships in biological material systems can ultimately assist us to develop novel materials with enhanced properties. For example, we recently demonstrated a bio-inspired scaled protective system that provides simultaneous mechanical protection and flexibility for locomotion.
For this particular award, we aim to uncover the principles of how echinoderms like starfish and sea urchins design and produce porous structures with minerals, which are extremely lightweight yet damage-tolerant. The insights obtained in this study will provide important lessons for the design and fabrication of novel synthetic, low-density materials for applications like lightweight structures, porous scaffolds, protection panels, etc.
What do you find most interesting about your field of engineering?
In relation to my research, the aspect that I enjoy most for mechanical engineering is its unique integration of both fundamental scientific discovery and applied engineering problem-solving. It’s fascinating to see how natural systems solve their mechanical engineering problems with limited resources, and how such understanding can teach us to rethink our current mechanical engineering solutions.
If you had one piece of advice to give students that aspire to pursue research and are just starting their journey, what would you share with them?
Always try to balance between depth and breadth during the academic training. While digging deeper to make your original contributions to one or two research topics, try to absorb more knowledge outside of your field by talking to people, going to seminars, reading papers and books, and watching documentaries.