NANOINDENTATION OF SOFT TISSUES AND OTHER BIOLOGICAL MATERIALS - Nanoindentation with Biological Applications - page 313

quantitative mechanical properties will be measured in these complex
materials using nanoindentation.
The breadth of data in the field shows that nanoindentation, at a
minimum, provides a valuable method for characterizing mechanical
behavior of biological materials at the nano- and microscales, mapping
properties in small biological samples, and comparing different tissue
regions after disease or repair. Whether the quantitative values reported
in many of these studies are meaningful as absolute quantitative values is
still uncertain, but the qualitative trends still answer many valuable
research questions. Future developments in instrumentation and
nanoindentation models tailored specifically to soft tissues and other
classes of biological materials will lead to improved confidence in
quantitative analyses of the mechanical properties of biological materials
at small length scales.

Acknowledgements
Unpublished work presented in this manuscript was supported by a
Denny Dickenson Orthopaedic Scholarship, a grant from the Orthopedic
Research and Education Foundation, and a Giannini Family Foundation
Medical Research Fellowship ( Fig. 9-2 ) and the Air Force Office of
Scientific Research (AFOSR), the Office of Naval Research (ONR), and
a National Research Council Postdoctoral Associateship ( Figs. 9-3 and
9-6 ) . DME would like to thank Michelle Oyen for valuable comments on
early drafts.

References
1. E. Gorb, K. Haas, A. Henrich, S. Enders, N. Barbakadze and S. Gorb, J. Exp. Biol.

208 , 4651 (2005).

2. G. Binnig, C. F. Quate and C. Gerber, Phys. Rev. Lett. 56 , 930 (1986).

3. N. A. Burnham and R. J. Colton, J. Vac. Sci. Technol., A 7 , 2906 (1989).

4. W. R. Bowen, R. W. Lovitt and C. J. Wright, Biotechnol. Lett. 22 , 893 (2000).

5. A. Vinckier and G. Semenza, FEBS Lett. 430 , 12 (1998).

6. W. C. Oliver and G. M. Pharr, J. Mater. Res. 7 , 1564 (1992).

7. D. M. Ebenstein and L. A. Pruitt, Nano Today 1 , 26 (2006).

8. R. J. Moon, C. R. Frihart and T. Wegner, Forest Prod. J. 56 , 4 (2006).