Christopher Barrett

Primary Research Theme: Bioengineering
Secondary Research Theme: Materials and Structures
Research Group/Lab : Biomimetic Materials Laboratory

KEYWORDS: • Mechanics of Biological Materials • Biomimetics • Fracture Mechanics • Composites • Experimental Mechanics • Small-scale Mechanical Testing •Multiscale Modeling

Nature produces extremely efficient natural, which are increasingly becoming a source of inspiration for engineers. In materials science, biomimetics (the science of imitating nature) is now starting to inspire novel materials with extraordinary mechanical properties.

My research focuses on the mechanical performance of hard biological materials (seashells, teeth), and on the development of novel "bio-inspired" composites. Hard biological materials are 10 to 10,000 times tougher than the fragile ceramics of which they are made. These levels of improvement are currently not matched by man-made materials, but nature demonstrates that they are possible.

Seashells and teeth are two very good examples of hard and tough natural materials. In order to determine which key microstructural features and mechanisms control their performance, we use small scale and in-situ experiments, and multiscale modeling. The focus is currently on toughening mechanisms, which are the mechanisms operating together to slow down or even stop the propagation of cracks within the material.

Using what we are learning from nature, we are developing novel bio-inspired composite materials: large scale model materials to demonstrate key concepts, high performance composites, and ceramic coatings with enhanced adhesion  
The goal of this research is to design, prepare, and characterize polymers containing novel functional groups, with which one can fashion thin film micro-optical or bio-active devices. Relating the properties and performance of these structures and simple devices to the structure of the polymer can afford insight into the molecular origins of the optical and mechanical behaviour of polymer surfaces, interfaces, and thin films. By examining these structure/property relationships, one can also tailor the polymers to optimize the performance of a given device, with the eventual goal of rational design.

This research program employs classical methods of polymer synthesis, characterization, and thin film fabrication, as well as more specialized techniques of laser optics and surface analysis. The aim is for students to emerge with a solid background in polymer and physical chemistry, and to gain exposure to interdisciplinary problem solving techniques which lie at the interface between Chemistry, Physics, and Materials Engineering. In all projects, an emphasis is placed on developing the ability to communicate research results effectively, through the preparation of conference presentations and journal articles.