The compromise between stiffness and toughness for typical engineering materials as compared to those found in nature. Two examples of high-strength high-toughness hierarchical structures: CNT based fibers and nacre shells.

Nature provides insight into how precursors of highly contrasting properties can be combined through formation of hierarchical structures in order to achieve remarkable improvements in performance. An attractive feature of many natural materials is their simultaneously high stiffness and toughness. By contrast, in engineering materials toughness must generally be sacrificed to achieve high stiffness or strength, and vice versa. We adopt a multiscale experimental and computational approach to unravel the lessons of nature and apply them to the design of high strength high toughness hierarchical composite materials.

Specific interests include:

1. Carbon based nanocomposites. Development and study of hierarchical carbon nanotube based fibers and composites.
2. Mechanics of Biomaterials and Bio-Inspired Composites. Development of artificial nacre materials based on the study of the hierarchical designs found in nature.