Synthesis and characterization of hard magnetic soft hydrogels

A unique approach to synthesize novel hard magnetic soft hydrogels with higher water content is proposed. The hard magnetic soft hydrogel contains cross-linked macromolecules of gelatin and water with embedded strontium hexaferrite (SFO) particles. First, SFO nanoparticles are synthesized using the auto-combustion method. Subsequently, the particles prepared are added to the hydrogels with three different weight fractions. The hydrogels are subjected to mechanical and magnetic loadings to investigate the mechanical, and actuation behavior, respectively. In addition, the hydrogels are also subjected to cyclic magnetic loading in transverse and antiparallel directions. Based on the experiments, it is observed that the deflections of the hydrogels can be controlled remotely by varying magnetic fields. Moreover, this study can be utilized to design a hydrogel beam with variable particle concentrations that can form complex shapes.