Fig. 8
a Scheme of preparation of the PNIPAAm/TiNSs hydrogel with cofacially oriented TiNSs in a magnetic flux of 10 T using a the UV curing method. b Demonstration of the thermoresponsive deformations with unidirectional procession of an l-shaped symmetric PNIPAAm/TiNSs hydrogel actuator. (a, b were reproduced with permission from Ref. [60], © 2015 Nature Publishing Group). c Synthesis components of the photo-responsive PNIPAAm/TiNSs/AuNPs hydrogel actuator. Magnetic flux of 10 T was used for cofacially oriented TiNSs/AuNPs in a cylindrically processed hydrogel. d Schematic of the peristaltic craving of an earthworm-like hydrogel. These optical images were captured while the laser was scanned with 445 nm laser light (5.6 W/cm2 power density). e Hydrogel fabrication by using TiNSs/AuNRs, instead of AuNPs. The images show the hydrogel that is responsive to NIR light irradiated through a ≈ 2-nm-thick piece of meat. The optical images also illustrate the pre- and post-irradiation with 1064 nm NIR laser light (12 W/cm2 power density). (c–e were reproduced with permission from Ref. [72], © 2018 Wiley–VCH Verlag GmbH & Co. KGaA, Weinheim)