Characterisation of hydrogel scaffolds under compression

Although a variety of scaffolds have been developed in recent years for a range of applications, repair of load-bearing tissues, such as articular cartilage in the knee, is still in its infancy due to the exceptional demands on mechanical
strength and stiffness. Unfortunately, rigorous in-vitromechanical characterisation has often been superseded by invivo testing in animals, where the loading scenarios often bear little resemblance to those in human, which has significantly restricted the potential range of clinical applications. A comprehensive mechanical characterisation is essential if scaffolds are to be used for load-bearing applications.In this chapter, we report the characterisation of viscoelastic behaviour of hydrogel scaffolds. The key factors, including the effects of constraint, strain rate and sample microstructure, on the mechanical properties of ahydrogel scaffold will be investigated. Some of the latest techniques such as microCT imaging, in-situ image guided failure assessment and Digital Volume Correlation (DVC)will be explored in the characterisation of the hydrogel scaffold under uniaxial compression.