fig7

Figure 7. The anisotropic hydrogel actuators with bilayer structures. (A) Schematic representation of photothermally responsive and self-healing bilayer nanocomposite hydrogels. The bilayer nanocomposite hydrogel can be used as a flow valve. Reproduced with permission^[142]. Copyright 2019, Elsevier; (B) The preparation technology and deformation mechanism of ICAs-Fe₃O₄/p(NIPAM-ABP) hydrogel actuator. Reproduced with permission^[143]. Copyright 2023, American Chemical Society; (C) Preparation process of the TN/NC bilayer hydrogel actuator. Reproduced with permission^[144]. Copyright 2021, Wiley-VCH; (D) Schematic diagram of NIR-actuated bilayer PNIPAM-VLDH/PAAm hydrogels. Reproduced with permission^[42]. Copyright 2023, American Chemical Society. ICAs: Isotropic conductive adhesives; p(NIPAM-ABP): co-poly(isopropylacrylamide-4-benzoylphenyl acrylate); NIR: near-infrared; PNIPAM: poly(N-isopropylacrylamide); VLDH: vulcanized layered double hydroxide; PAAm: polyacrylamide.