A new method for real-time and in-situ characterization of the mechanical and material properties of biological tissue constructs

To capture the transient, nonlinear and time-dependent characteristics of the mechanical and material properties of biomaterials and biological tissue constructs, we developed a real-time based evaluation method. This method measures the paired transient stress and strain as a function of time for a given material, and calculates instantaneously its complex modulus measurements as a function of frequency. Because the measured complex moduli contain not only the mechanical properties (magnitude of the modulus curves) but also the material characteristics (shape of the modulus curves), this method allows us to link directly the mechanical properties to the material characteristics in a real-time and in-situ manner. The significance of this capability is that the changes in both mechanical property and material structure can be correlated repeatedly during the growing or aggregating processes of the biological tissues or constructs.