Could Effective Mechanical Properties of Soft Tissues and Biomaterials at Mesoscale be Obtained by Modal Analysis?
Résumé
Background
The mechanical properties of biological tissues and soft biomaterials are difficult to explore even though they play an important role in mechanobiological responses and organ homeostasis. Limited availability of harvested tissue and careful handling must be considered as well as discrepancies in biomaterial development.
Objective
We hypothesized that a mixed analytical-experimental modal analysis could be used to determine effective mechanical properties at the mesoscale for hydrated and fragile, poorly available and small-sized biological tissue and biomaterials.
Methods
Young's modulus E, shear modulus G and Poisson's ratio were obtained from the measurement of first two natural frequencies of a set-up associating tested specimen with a cantilever. Tangent modules are calculated using a set of two analytical governing equations in linear vibration framework. A complementary parametric sensitivity analysis was performed. The methodology was evaluated using materials known to be challenging, namely agarose for biomaterials and bone marrow for biological tissues.
Results
Frequencies were in the range of 350 Hz and acquisition time of few seconds. Linear responses was checked and solution triplets (E, G, nu) were (99 ± 10 kPa, 43 ± 0.3 kPa, 0.16 ± 0.1) for agarose and (61 ± 12 kPa, 28 ± 7 kPa, 0.07 ± 0.03) for bone marrow.
Conclusion
Comparisons with literature when available, confirmed approach acceptability. Limited influences of boundary conditions, brief experiments and reproducibility can be considered for applications to fragile and rare biomaterials and biological tissues, in addition to conventional characterization methods.