Sabrina Caria, Jessica Petiti, Federico Picollo, Carla Divieto
Hydrogels represent a unique class of materials characterized by their three-dimensional, hydrophilic polymer networks, which enable them to absorb and retain large quantities of aqueous solutions. While the literature is abundant with excellent works on the classification, preparation, and applications of hydrogels, a notable lack remains in comprehensive studies focused on their characterization. This gap contributes to heterogeneous results and conflicting fields. In this context, this review aims to provide a detailed and systematic overview of hydrogel characterization techniques. It begins with an exploration of physicochemical, morphological, and mechanical properties, followed by an examination of distinctive hydrogel features, biocompatibility, and application-based properties, particularly for testing applications within the biomedical field. By highlighting the significance of various characterization methods, this review seeks to enhance the understanding of hydrogels and guide future research efforts, ultimately facilitating the development of more effective hydrogel-based materials for several applications.