Structure-Function Analysis of an Ultra-Hard Biological Composite

University Of California-Riverside, Riverside CA

Investigators

Abstract

ID: MPS/DMR/BMAT(7623) 0906770 PI: Kisailus, David ORG: UC Riverside Title: Structure-Function Analysis of an Ultra-hard Biological Composite INTELLECTUAL MERIT: There is a need for new light-weight structural materials with high strength and durability that are low-cost and recyclable. Nature has evolved efficient strategies, exemplified in the mineralized tissues of numerous species, to synthesize materials that often exhibit exceptional mechanical properties. These biological systems demonstrate the ability to control nano- and microstructural features that significantly improve the mechanical performance of otherwise brittle materials. One such example is found in the hyper-mineralized combative dactyl club of the stomatopods, a group of highly aggressive marine crustaceans. This ultrahard organic-inorganic composite structure is capable of inflicting significant damage following impact with a wide variety of biomineralized structures (e.g., mollusk shells, crab exoskeletons, the skulls of small fish). This project combines expertise in a number of areas including biologically inspired materials synthesis, structural characterization, mechanical testing, solid-state nuclear magnetic resonance (NMR) spectroscopy, protein-mineral interaction modeling, and a thorough knowledge of the biological system to be studied. Using these approaches, the project will investigate the structure-property relationships of the hyper-mineralized stomatopod dactyl clubs and elucidate the primary toughening mechanisms of these unique composite materials through the following potentially transformational investigations: (1) A detailed, three-dimensional map of the nano- and microstructural features, with specific mineral composition and phase information. (2) A complementary mechanical investigation of the regional structures. (3) In-vitro mineralization experiments to understand organic-inorganic interactions that control mineral composition and phase. BROADER IMPACTS: This strongly interdisciplinary research has the potential to enable significant progress in the emerging fields of nanotechnology and nanomanufacturing by exploiting control mechanisms established by nature to make novel materials and devices exhibiting paradigm-shifting properties. By investigating the structure-property relationships of these unique impact-tolerant mineralized structures using modern chemical, morphological, and mechanical characterization techniques, the long-term aim will be to develop the necessary tools for the design and fabrication of cost-effective and environmentally friendly engineering materials that mimic the various design elements and performance properties present in biological systems. The PI, a new faculty member at UC Riverside, has demonstrated an ability to attract a diverse group of students to his lab. Of the six graduate students, three are female. He has 12 undergraduates working in his lab, including four females, four Hispanics, and two African Americans. The co-PI has an equally strong record in attracting a diverse group of students. The UC Riverside campus is noted for its success in attracting underrepresented minorities to a Research I environment and seeing them complete their studies successfully. Encouragement of undergraduate research is an important component of this success, and both PIs are making strong contributions. Although not required of proposals submitted prior to January 5, 2009, the proposal describes a clear and effective plan for training of the postdoctoral who will be trained on the project. The PI has also described plans for involving high school students and teachers from the diverse community surrounding the university in his research. A web camera set up in the Kisailus lab will enable students in local and more distant high schools to observe the stomatopod rearing facilities and the experimental research as it progresses.