Characterizing the Relaxation Behavior of Double-Network Hydrogels under Large Deformation by Indentation Test

Abstract In recent years, instrumented indentation technique has been widely applied in the mechanical characterization of hydrated soft materials such as hydrogels and bio-soft tissues. However, the indentation measurement technique and properties evaluation methods for this kind of materials undergoing large deformation have not been well developed. Applying the indentation load-relaxation experiments, this paper studied the relaxation behaviors of calcium alginate/polyacrylamide double-network hydrogels under large spherical indentation deformation. The effects of temperature on the relaxation properties of calcium alginate/polyacrylamide double-network hydrogels were also measured and evaluated. This work not only helps to improve the understanding of the relaxation properties of double-network hydrogels under large deformation conditions, but also has certain guiding significance for the development of the instrumented indentation testing technology of soft materials.