Michelle L. Oyen of Cambridge University Engineering Department will present
the talk "Probing the Soft Side with Nanoindentation Techniques" on Wednesday,
March 24 at 3 p.m. in Maryland Hall 110.
Dr. Oyen is a lecturer in Mechanics of Biological Materials in the Mechanics
and Materials Division and the Engineering for the Life Sciences group at Cambridge
University. This seminar is hosted by Professor Tim Weihs and the Johns
Hopkins University Department of Materials Science and Engineering. The
talk is free and open to all Johns Hopkins faculty, staff and students.
The mechanical properties of many "soft" materials are of interest
for biomedical applications, including both natural tissues and hydrogels for
tissue engineering applications. In the last 15 years, nanoindentation techniques
have gained prominence in the mechanical testing community for three reasons:
first, the fine resolution in load and displacement transducers, second the
fine spatial resolution for mapping local mechanical properties, and finally
the relative ease of performing mechanical testing. In the current studies,
we extend the scope of nanoindentation testing with commercial indenters to
quantitative measurements on kPa materials. Different forms of the material
constitutive response were considered with an emphasis on time-dependent viscoelastic
or poroelastic deformation. Applications are the considered for hydrated tissues
and hydrogels including articular cartilage, bone and mechanically graded hydrogels.
Further investigations using adaptations of these nanoindentation techniques
examine nano-scale adhesion and mechanical outcomes in stem cell differentiation.
This study demonstrates the potential for high-throughput mechanical screening
of soft materials and for mapping property gradients in inhomogeneous materials
as these approaches can now be extended to materials in the kilopascal elastic