Biomedical Engineering Reference
In-Depth Information
CHAPTER 1
INTRODUCTION
Tamaryn A.V. Shean, Michelle I. Oyen and Michael F. Ashby
Department of Engineering, Cambridge University
E-mail:
tavs2@cam.ac.uk
This introductory chapter provides background to motivate the study of
biological materials with nanoindentation techniques. The reasoning
behind investigations of the mechanical behavior of biological
materials is introduced, as are the particular reasons for conducting
these investigations at small physical length-scales. A taxonomy for
biological materials is presented, emphasizing a top-down hierarchical
system for classification, from organs to tissues and down in scale,
including the molecular building blocks for both cells and extracellular
matrix material. Typical implementation of nanoindentation testing is
described and limitations in applying the technique to biological
systems are presented. This overview motivates the content contained
in the remainder of this volume, including investigation of fundamental
contact mechanics principles appropriate to biological systems and
application of nanoindentation techniques to the characterization of
biological materials.
1. Introduction
There are many naturally occurring materials with fundamental
mechanical functions. Both people and plants have structural skeletons;
many shells and some bones (
i.e.
the ribcage and skull) provide
protection for delicate organisms or internal organs. There has been
recent growth in the measurement of mechanical properties of natural
materials with structural functions,
1-4
in the context of trying to
understand how these materials respond to mechanical forces and
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