Figure 8.

Rheological behaviors of the agarose/AM/Laponite 4D ink at 95 °C. Flow rheology pattern showing viscosity against shear rate (a). Oscillatory rheology pattern showing shear storage modulus (G′) and shear loss modulus (G″) evolution of inks used, increasing shear strain (b). Oscillatory rheology pattern showing modulus evolution of inks between 1% and 300% strain (c). The storage modulus variation of 4D ink during cooling (d). Four-dimensional printing product printed by 4D ink: a whale-like hydrogel was used as a model schematic for the 4D transition process (e), the softening and hardening cycles of an octopus-like gel (f), the storage modulus (e) variation of 4D gel during heating and cooling cycles measured by rheology (g). Reproduced from [152] with permission.