fig5

Figure 5. The anisotropic hydrogel actuators with oriented structures. (A) Schematic diagram of the two-physical-phase type 3D-connected conductive network enriched with CNTs. Reproduced with permission^[122]. Copyright 2020, Royal Society of Chemistry; (B) Schematic of the preparation and deformation of CNT/PNIPAM composite hydrogel and the morphology of an exemplar CNT/PNIPAM actuator (i) below T_c of PNIPAM, (ii) above T_c while surface PNIPAM, and (iii) above T_c while free. Reproduced with permission^[123]. Copyright 2022, Wiley-VCH; (C) Schematic diagram of the anisotropic hydrogel based on Ag NPs preparation process; (D) Schematic diagram and driving demonstration of robot hand assembled by different directions of hydrogel through healing effect. Reproduced with permission^[32]. Copyright 2019, Springer Nature Publishing Group; (E) Schematic diagram of the preparation of anisotropic hydrogel composites driven by magnetic nanoparticles. Reproduced with permission^[124]. Copyright 2022, Wiley-VCH; (F) Schematic of the synthesis process of PMD hydrogel. Reproduced with permission^[40]. Copyright 2023, Wiley-VCH. 3D: Three-dimensional; CNTs: carbon nanotubes; PNIPAM: poly(N-isopropylacrylamide); Ag NPs: silver nanoparticles; PMD: PNIPAM/MXene directional.