At the Biomimetic Materials Lab we study the structure, performance and mechanics of biological materials using a wide range of experimental and modeling techniques. Focus is currently on deformation and fracture, but other functionalities such as self-healing are also studied. In parallel we design, optimize, fabricate and test new engineering materials inspired form nature. These materials possess new and attractive combinations of properties such as toughness, strength, stiffness and light weight. Other functionalities such as self-healing, adaptivity to stress or actuation and shape morphing can also be incorporated. Nature also show us how to make high-performance sustainable materials with a minimum amount of ingredients and at ambient temperatures and pressures, which can also be recycled an infinite number of times.


  
Structure and Mechanics of Nacre from Mollusk Shells


Nacre is mostly made of a brittle mineral with a small fraction of organic materials. The microstructure of nacre such that its toughness is 3,000 times higher than the mineral of which it is made, approaching the toughness of advanced engineering ceramics such as zirconia. This type of improvement or “toughness amplification” is currently unmatched by manmade materials, and for this reason nacre is considered one of the best models for future high-performance biomimetic composites.





We are studying the mechanics of nacre across different length scales using combinations of experiment and modeling. For example, we have recently demonstrated how the microstructure of nacre "amplifies" the toughness of its components.







  
Synthetic Nacre


We are designing, fabricating and testing synthtic materials that mimic the structure of nacre. Successful duplication of key mechanisms yield materials with unusual and attractive properties. For example, we have recently fabricated a composite made of of 95% of brittle material, but which fails at tenisle strains exceeding 10% . We are currently fabricating similar structures at the microscopic scale (which is more challenging!)






  
Mechanics of Fish Scales

In the search for high performance natural materials that could serve as models and bioinspiration, fish scales have been surprisingly overlooked in the biomimetic research community.  In this project we have measured, for the first time, the performance of fish scales in the event of a bite from a predator. We found that scales resist penetration better than high-performance light-weight impact-resistant polymers such as polycarbonate and polystyrene. Fish scales could therefore serve as inspiration for new light, flexible and tough protective armors. Under severe contact stresses (as would occur from a predator’s bite) the outer bony layer of the scale cracks in a highly controlled fashion first, forming four well defined “flaps”. The deflection of these flaps under the biting force of a predator’s tooth is resisted by the underlying collagen layer, which acts as a retaining membrane. We are currently duplicating these powerful mechanisms in novel protective systems.




 
Other Projects... more details soon!


Mechanics of biological interfaces
Bio-inspired Fiber Composites
Bio-inspired hybrid armor systems
Damage accumulation in individual collagen fibrils




 
Funding





                                














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McGill University
McGill Faculty of Engineering | Department of Mechanical Engineering

Francois Barthelat | MacDonald 150| 817 Sherbrooke Street West | Montreal, Quebec H3A 2K6| Canada
Phone: 514-398-6318 Fax: 514-398-7365