fig5

Figure 5. Demonstration of the toughness of hydrogels. (A) A series of optical images showing an egg of 60 g impacting onto a printed web from a height of 1 m and it remaining intact. (B) Tensile stress-strain curves, with the corresponding (ii and v) fracture stress and strain and (iii and vi) toughness and elastic modulus of the PEC and DPC-Mg hydrogels prepared with various cAAc^[49]. (C) CTS/P(AA-HEMA) organogels with extraordinary mechanical properties. (i) Original organogel and after stretching over 10,000%. (ii) An organogel compressed and immediately recovered to its original state after releasing the stress. (iii) Two organogels tied together and stretched. (iv) Loading-unloading experiments of CTS/P(AA-HEMA) organogels during five successive loading-unloading cycles at a set strain of 1500%^[50]. (A) Reproduced with permission^[44]. Copyright 2018, ACS. (B) Reproduced with permission^[49]. Copyright 2020, Elsevier. (C) Reproduced with permission^[50]. Copyright 2020, Elsevier.