α,ε-Hybrid Peptide-Stabilized Magnetic Nanoparticle-Coated Paper-Based Actuators

The development of α,ε-hybrid peptide-stabilized magnetic nanoparticles and their application to fabricate a paper-based actuator has been reported. From single-crystal diffraction analysis, the nitropeptide 2 has an extended structure with a trans geometry. The one-pot in situ multiple oxidation–reduction reaction of a synthetic nitropeptide solution in ammonium hydroxide and FeCl2 leads to the formation of Fe3O4 nanoparticles. The reduction reaction replaces the nitro group with an amine group, which finally acts as capping agent for the stabilization of the Fe3O4 nanoparticles. Paper-based soft magneto machines with multivariant actuation modes such as contraction–expansion, bending, and uplifting locomotion have been studied. The device has potential as controllable paper-based soft robots.