Towards mechanical characterization of nano-scale interfaces in biocomposite materials.

• Applicant: Dr. Igor Zlotnikov
• Subject Area: Polymeric and Biogenic Materials and Derived Composites ; Materials in Sintering Processes and Generative Manufacturing Processes ; Mechanical Properties of Metallic Materials and their Microstructural Origins
• Term: from 2020 to 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 443727504

• Final Report Year: 2024

Final Report Abstract

Identifying the property‐structure‐function relationships in mineral‐organic biocomposite materials is one of major challenges in today's biomaterials science that incorporates research efforts in biology, chemistry, physics, and engineering. The cross-disciplinary interest in the topic stems from the efficiency of the biochemical machinery that is responsible for biotic mineral formation, the unconventional functional capacity of these tissues and, at the same time, elegance and even simplicity of “engineering” solutions it provides to the organisms. Specifically, nature is successful in forming complex hierarchical biocomposites with superior mechanical properties that provide the animals with high stiffness, high toughness and in some cases, are adapted for functional requirements that involve viscous damping, such as impact absorption, signal filtering and vibrations inhibition. In highly mineralized tissues, the stiff and hard mineral building blocks at all hierarchical levels are usually joined together by ultra thin compliant, soft and viscoelastic organic interfaces that, in some cases, are only a few nanometers thick. Although these interfaces comprise merely a small volume fraction of the biocomposite structures, the performance of the entire tissue is considered to be substantially affected by their mechanical characteristics. However, our understanding of the contribution of the organic interfaces to the mechanical functionality of these biocomposite assemblies is limited, mainly, because we still lack the capacity to assess their nano-mechanical properties. The project was driven by the goal of developing experimental‐numerical and experimental‐ analytical strategies to characterize the properties of organic interfaces in biocomposite architectures. To achieve this aim, we studied mineral-organic architectures taken from different organisms. The investigations were carried out by adapting and reinventing state-of-the-art nanoscale mechanical characterization techniques and were supported by extensive numerical and theoretical analysis. The outcomes of this research not only allowed us to answer an outstanding question in the field of biological materials, but are also expected to have a fundamental impact on future study and design of classical materials systems.

Publications

• Semi-empirical formulation of contact with an interphase boundary. Extreme Mechanics Letters, 50, 101541.
  Tadayon, K.; Lemanis, R.; Bar-On, B. & Zlotnikov, I.
  
• In Situ Nanoindentation at Elevated Humidities. Advanced Materials Interfaces, 10(33).
  Tadayon, Kian; Bar‐On, Benny; Günther, Björn; Vogel, Cordula & Zlotnikov, Igor
  
• Nanoscale dynamic mechanical analysis on interfaces of biological composites. Journal of the Mechanical Behavior of Biomedical Materials, 146, 106091.
  Braunshtein, Ofer; Levavi, Liat; Zlotnikov, Igor & Bar-On, Benny