In　this　paper,　we　fabricated　a　tough,　anti-freezing　(freezing　point　of　− 25.5 °C)　and　ionic　conductive　carboxymethyl　chitosan　(CMCS)-based　double-network　(DN)　hydrogel　by　a　free　radical　polymerization　and　Al3+　coordination.　In　greater　detail,　the　PAM/CMCS-Al3+　hydrogel　was　composed　of　Al3+-coordinated　CMCS　network　and　covalently　crosslinked　PAM　network.　The　hybrid　DN　structure　of　PAM/CMCS-Al3+　hydrogel　gave　rise　to　high　mechanical　properties　(tensile　strength　up　to　2.15 MPa,　elongation　at　break　up　to　1741%,　toughness　of　13.2 MJ/m3　and　elastic　modulus　of　1.43 MPa)　and　good　fatigue　resistance.　PAM/CMCS-Al3+　hydrogel　not　only　exhibited　the　capacity　to　conduct　electricity　via　free　ions,　but　also　had　good　strain　sensitivity　(GF　=　2.09,　0–200%　strain　and　fast　response　time　of　234 ms).　Based　on　the　high　strain　sensitivity,　PAM/CMCS-Al3+　hydrogel　could　be　used　to　assemble　a　flexible　strain　sensor　with　the　ability　to　precisely　detect　human　motions.Kindly　check　and　confirm　the　edit　made　in　the　title.We　agree　with　the　edit　made　in　the　title.　©　2022,　The　Author(s),　under　exclusive　licence　to　Springer　Science+Business　Media,　LLC,　part　of　Springer　Nature.