BIOLOGICAL MATERIALS SCIENCE Biological Materials Bioinspired Materials and

BIOLOGICAL MATERIALS SCIENCE Biological Materials, Bio-inspired Materials, and Biomaterials Marc André Meyers Po-Yu Chen

Chapter 1 Evolution of materials science and engineering: from natural to bioinspired materials 1. 1 Early developments 1. 2 Evolution of materials science and engineering 1. 2. 1 Traditional metallurgy 1. 2. 2 The structure–properties–performance triangle 1. 2. 3 Functional materials 1. 3 Biological and bioinspired materials

Biological Materials Science n Biomaterials: Materials specifically designed for optimum compatibility with biological systems (e. g. implants) n Biological (Natural) Materials: Materials and systems encountered in nature (e. g. bone & teeth) n Bio-inspired (Biomimetic) Materials: Approaches to synthesize novel materials inspired from biological systems in nature ¨ ¨ 1) biomimicking – learning from biological systems to make new materials using current technology 2) bioduplication - new methodologies, such as genetic engineering used to produce an entire new class of materials. Skeleton of the deep sea sponge Euplectella • Swiss Re Tower in London • Hotel Arts Barcelona • Eiffel Tower in Paris Aizenberg et al. science 2005; 309: 275

One of the earliest tools, a chopper, ~ 2 M years from the Olduvai Gorge; British Museum.

Strength vs. density Ashby plots of pre-historic synthetic materials

Strength vs. density Ashby plot of contemporary synthetic materials

Metallurgical triangle: traditional technology of past centuries

Leonardo’s Vitruvian Man and four classes of biomaterials

The materials science and engineering revolution: a unified approach to metals, ceramics, and polymers (a) The original Cohen structure–properties–performance triangle (b) a modernized version.

The Materials Science & Engineering Tetrahedron

Distinguishing Features of Biological Materials n Hierarchical structure n Multi-functionality n Self-assembly/self-organization n Synthesis under mild conditions n Importance of hydration n Basic building blocks ¨ ¨ Minerals n Calcium carbonate (Ca. CO 3) n Calcium phosphate (hydroxyapatite Ca 10(PO 4)6(OH)2) n Silica (Si. O 2) n Magnetite (Fe 3 O 4) Proteins n ¨ Collagen, keratin, elastin Polysaccharides n Cellulose, chitin

Biological materials science at the intersection of physics, chemistry, and biology

Biological material Light elements dominate: C, N, O, H, P, S Ca, Si, Mg… Engineering material Large variety of elements: Fe, Cr, Ni, Al, Si, C, N, O Growth by biologically controlled Fabrication from melts, powders, self-assembly (approximate design) solutions, etc. (exact design) Ambient temperature Elevated temperature strategies Hierarchical structuring At all levels Forming (of the part) and microstructural management (of the material) Adaptations: Of form and structure to the function Selection of material according to function Modeling and remodeling capability of adaptation to changing Secure design: environmental conditions (Considering possible maximum loads as well as fatigue, etc. ) Healing: Capability of self repair P. Fratzl, J. R. Soc. Interface, 4[15] 637 -642 (2007).

Summary n n Early humans used exclusively natural materials, the majority of which were biological: wood, bone, hide, tendons and ligaments, horns, and antlers. The earliest vestiges of industrial-scale production of copper are from Jordan. This marked the beginning of the use of metals and alloys as a major class of materials. Biological materials have seven unique and defining features: (i) self -assembly; (ii) self-healing capability; (iii) evolution and environmental constraints; (iv) hydration; (v) mild synthesis conditions; (vi) functionality; (vii) hierarchy. Although our synthetic materials have properties that far exceed those of biological materials, the latter have ingenious designs that evolved through millions of years. Thus, we are developing a new class of bioinspired materials that apply the internal design principles of biological materials but use synthetic synthesis and processing methods.