Chapter 3: Characterizations of Hydrogels

Hydrogels are combinations of polymeric networks that have been physically or chemically crosslinked with each other and have a three-dimensional (3D) mesh structure that can absorb a large amount of water while maintaining the overall configuration of the hydrogel. Hydrogels have attracted the attention of researchers worldwide owing to their various potential applications, including drug delivery, tissue regeneration, biosensor, 3D bioprinting, cell therapy, and 3D cell culture, depending on their physical and chemical features. To exploit this unique type of material, knowledge regarding its exclusive properties, as well as how these properties can be adjusted to accomplish different objectives, is crucial. Moreover, as numerous properties of hydrogels are considered critical to their applicability, it is important to utilize appropriate instruments and methods to evaluate such properties. In this chapter, we examine the various properties of hydrogels and discuss how these properties can be characterized.