Mechanical Properties Of Biomaterials

This brief introductory chapter provides a broad overview of materials, biomaterials and the need to understand different techniques to characterize biomaterials. From this chapter, the reader can gain a perspective on how the rest of the topics in different chapters are divided to fully comprehend this inherently multidisciplinary field. Application of appropriate characterization tools can not only save time to fully evaluate different biomaterials, it can also make commercial biomedical devices safer. In the long run, safer biomedical devices can only reduce the pain and suffering of mankind, a dream that resonates with every biomedical researcher.

Structural Biomaterials: Properties, Characteristics, and Selection serves as a single point of reference to digest current research and develop a deeper understanding in the field of biomaterials engineering. This book uses a materials-focused approach, allowing the reader to quickly access specific, detailed information on biomaterials characterization and selection. Relevant to a range of readers, this book provides holistic coverage of the broad categories of structural biomaterials currently available and used in medical applications, highlighting the property requirements for structural biomaterials, their biocompatibility performance and their safety regulation in key categories such as metals, ceramics and polymers. The materials science perspective of this text ensures the content is accessible even to those without an extensive background in applied medicine, positioning this text not just for students, but as an overview and reference for researchers, scientists and engineers entering the field from related materials science disciplines. Provides a unique, holistic approach, covering key biomaterials categories in one text, including metals, ceramics and polymers Discusses advantages, disadvantages, biocompatibility performance and safety regulations, allowing for accurate materials selection in medical applications Utilizes a materials science perspective, allowing those without an extensive applied medical background to learn about the field

This book gives a fundmaentally comprehensive introduction to most of the important biomaterials including ceramics, metals, and polymers.

Contains 23 papers presented at the May 1992 symposium in Pittsburgh, PA. Covers issues in biomaterials science such as polyurethanes, metal components, novel plastics, coatings, bioresorbable materials, and testing methods. Discusses future directions in the field, such as the design and fabricatio

Focusing on bone biology, Bone Tissue Engineering integrates basic sciences with tissue engineering. It includes contributions from world-renowned researchers and clinicians who discuss key topics such as different models and approaches to bone tissue engineering, as well as exciting clinical applications for patients. Divided into four sections, t

This book provides tabular and text data relating to normal and diseased tissue materials and materials used in medical devices. Comprehensive and practical for students, researchers, engineers, and practicing physicians who use implants, this book considers the materials aspects of both implantable materials and natural tissues and fluids. Examples of materials and topics covered include titanium, elastomers, degradable biomaterials, composites, scaffold materials for tissue engineering, dental implants, sterilization effects on material properties, metallic alloys, and much more. Each chapter author considers the intrinsic and interactive properties of biomaterials, as well as their appropriate applications and historical contexts. Now in an updated second edition, this book also contains two new chapters on the cornea and on vocal folds, as well as updated insights, data, and citations for several chapters.

"This book should go a long way towards filling the communication gap between biology and physics in the area of biomaterials]. It begins with the basic theory of elasticity and viscoelasticity, describing concepts like stress, strain, compliance, and plasticity in simple mathematical terms. . . . For the non-biologist, these chapters provide a clear account of macromolecular structure and conformation. . . . Vincent's work] is a delight to read, full of interesting anecdotes and examples from unexpected sources. . . . I can strongly recommend this book, as it shows how biologists could use mechanical properties as well as conventional methods to deduce molecular structure."--Anna Furth, The Times Higher Education Supplement In what is now recognized as a standard introduction to biomaterials, Julian Vincent presents a biologist's analysis of the structural materials of organisms, using molecular biology as a starting point. He explores the chemical structure of both proteins and polysaccharides, illustrating how their composition and bonding determine the mechanical properties of the materials in which they occurincluding pliant composites such as skin, artery, and plant tissue; stiff composites such as insect cuticle and wood; and biological ceramics such as teeth, bone, and eggshell. Here Vincent discusses the possibilities of taking ideas from nature with biomimicry and "intelligent" (or self-designing and sensitive) materials.

The design of biomedical devices almost always involves some form of mechanical characterization of biomaterials. This chapter provides a broad overview of experimental methods and important considerations for mechanical characterization of biomaterials, with special attention to the practical needs of engineers and scientists who encounter a need to characterize the mechanical properties of a biomaterial but may not know where to begin or what the key considerations should be. Many details are necessarily omitted from this broad overview, but numerous references are provided for greater technical depth on a particular topic, standardized methodologies, and exemplary studies. Fundamental concepts are introduced, beginning with stress and strain versus force and displacement. The mechanical properties measured from a stress–strain curve, different types of stress–strain curves, and corresponding constitutive models are reviewed, including differences in material classes and anisotropy. Three primary methods of analysis for fracture mechanics are introduced, including stress concentrations, energy criteria for crack initiation and propagation (fracture toughness), and statistical methods for the probability of fracture. The mechanical characterization of biomaterials begins with selection and preparation of standardized test specimens, which are critical to obtaining accurate and reproducible measurements of material properties. Practical considerations are outlined for selection and preparation of the specimen size, geometry, surface finish, and precracking. The mechanical characterization of biomaterial test specimens always involves the application and measurement of load and deformation. Practical considerations are outlined for the selection and use of load frames, load cells, load fixtures, extensometers, and strain gauges. A number of common loading modes are introduced and compared: uniaxial tension, uniaxial compression, biaxial tension, torsion, diametral compression, three-point bending, four-point bending, and in-plane shear (including biomaterial-tissue interfacial shear strength). Strain-rate sensitivity or time-dependent behavior can profoundly influence stress–strain behavior and thus measured mechanical properties. The effects of high strain rates may be characterized by impact testing using a pendulum, drop tower, or split Hopkinson pressure bar. The effects of low strain rates may be characterized by creep deformation or creep rupture tests. The time-dependent behavior of viscoelastic materials is introduced, including creep, stress relaxation, common constitutive models, and practical considerations for testing. The frequency of loading, or cyclic loading, is another aspect of time-dependent behavior, which is critical for mechanical characterization of biomaterials, leading to fatigue deformation and failure or viscoelastic creep and stress relaxation. Practical considerations are described for selecting the waveform, frequency, cyclic stress/strain levels, loading mode, and test duration. Common methods are introduced for fatigue lifetime testing (including S-N curves, notch factors, and fatigue damage), fatigue crack propagation, and dynamic mechanical analysis (DMA). Nondestructive tests are particularly useful for sampling small volumes of a biomaterial (e.g., implant retrieval or biopsy) or characterizing spatial heterogeneity in mechanical properties. Various indentation tests and indenter geometries are introduced and compared, including classic hardness (Brinell and Rockwell), microhardness (Knoop and Vickers), and instrumented nanoindentation (Berkovich, cube corner, etc.). Methods and limitations are described for characterizing the reduced modulus, viscoelasticity, and fracture toughness using indentation. Ultrasonic wave-propagation methods are also introduced with an emphasis on methods for characterizing anisotropic elastic constants. Biomaterials are typically subjected to various sterilization methods prior to service and an aqueous physiological environment in service. Therefore, the effects of temperature, pressure, various aqueous media (water, phosphate buffered saline (PBS), media, foetal bovine serum (FBS), lipids, etc.), and irradiation on mechanical characterization of biomaterials are considered, including the degradation of mechanical properties by various mechanisms involving water uptake, hydrolysis, and oxidation. Finally, methods and guidelines are provided for data acquisition from transducers and data analysis, including an introduction to some basic statistical methods.

Introductory Biomaterials enables undergraduate students in Biomedical, Chemical, Materials and other relevant Engineering disciplines to become familiar with the key concepts of Biomaterials principles: biocompatibility, structure-property-applications relationships, mechanical response of natural tissues, and cellular pathways for tissue-material ingrowth. Written in a clear, concise manner that weds theory with applications, this book helps students to understand the often intricate relationships between materials the implant devices that are made from them, and how the human body reacts to them. The book includes such concepts as requirements for metals, alloys, and ceramic materials to be used in load bearing implants (corrosion concepts, stress shielding, mechanical properties, composition), what properties of polymers impact their use in medicine (leaching and swelling, creep and stress relaxation); the tissue response to biomaterials, concepts related to drug delivery applications (polymer degradation, encapsulation), and tissue engineering (scaffold porosity, diffusion of nutrients, mechanical properties). Begins with structure-properties, followed immediately by their impact on actual biomaterials classes and devices, thus directly relating theory to applications (e.g. polymers to polymeric stents; metals to fracture fixation devices) Explains concepts in a clear, progressive manner, with numerous examples and figures to enhance student learning Covers all key biomaterials classes: metallic, ceramic, polymeric, composite and biological Includes a timely chapter on medical device regulation