Just published in this month's Journal of Materials Research--a study on poroelastic nanoindentation characterization for hydrated bone samples.  Poroelastic problems are notoriously difficult to incorporate into routine materials characterization due to the paucity of problems with closed-form solutions.  However, in some cases, a master-curve does exist and parameter identification can be accomplished without requiring inverse finite element analysis and optimization for every condition.  The abstract follows, linked from here .

Poroelastic nanoindentation responses of hydrated bone, J. Mater. Res. 23 (2008) 1307.

The review paper, "Viscoelastic effects in small-scale indentation of biological materials" has been published in International Journal of Surface Science and Engineering 2007 - Vol. 1, No.2/3 pp. 180 - 197 .  This work presents both a review of analytical (linear) viscoelasticity in the context of contact-probe mechanical characterization and summarizes the available literature on application of these techniques to measurements of biological material creep and relaxation responses.