Fig. 2.

Biomimetic stimuli responsive soft grippers composed of poly N-isopropylacrylamide (pNIPAM) based hydrogels hybridized with nanoparticles. a Programmable folding cube composed of single-walled carbon nanotube (SWNT)-pNIPAM and low-density polyethylene (LDPE) bilayer that actuates reversibly in water (reproduced with permission [66]. Copyright 2011, American Chemical Society). b Multi near-infrared light (NIR), ionic strength (IS), and temperature change responsive soft gripper composed of graphene oxide (GO)-pNIPAM and pNIPAM-poly(methylacrylic acid)(PMAA) bilayer (reproduced with permission [65]. Copyright 2016, Wiley–VCH). c Thermoresponsive biomimetic flower shaped fluorescent color displaying soft gripper composed of graphene oxide (GO)-pNIPAM and pH responsive perylene bisimide-functionalized hyperbranched polyethylenimine (PBI-HPEI) hybrid bilayer (reproduced with permission [68]. Copyright 2017, Wiley–VCH). d Temperature-controlled pNIPAM/pNIPAM-co-clay nanocomposite bilayer hydrogel gripper that grips a moving pearl

(reproduced with permission [22]. Copyright 2015, Wiley–VCH)