The topic gained traction from 2003 onwards, when the groups of Gong, Creton, Schmidt, and others elaborated on the concepts of double networks and nanocomposite hydrogels. Specifically, Gong et al. demonstrated for the first time how hydrogels with extremely high mechanical strength can be accessed by using a double network architecture. In 2012, Suo and co-workers presented double networks combining covalent and physical cross-links, which -together with the previous workspioneered this relatively young area of research, sparking a surge of studies thereafter. In the following year, the number of publications quadrupled and just in 2022 reached 564 publications.