Highly Magnetic Hydrogel Composites for Magnetic Actuators or Artificial Muscle Applications

Magnetic and electrically conducting polymer composites offer significant advantages over their metallic or ceramic counterparts. Therefore they offer alternatives in a wide range of potential applications such as magnetic actuators, electronic devices, or even artificial muscles.

This contribution reports on the preparation of highly magnetic hydrogel polymer composites. Similar to previous studies on magnetic polymers [1] carbon coated cobalt nanoparticles [2-3] were directly incorporated into the polymerization of 2-hydroxyethyl methacrylate (HEMA). To overcome the characteristic problem of the homogeneous dispersion of the nanoparticles in the polymer, the carbon shell of the particles was covalently functionalized [2] with an organic component similar to the monomer. Later favored the in-situ polymerization of the particles with the monomer and resulted in the formation of a highly magnetic and mechanical stable polymer. Regarding the used mold, different polymers (30 wt% nanoparticles with respect to monomer) could be produced, which could offer an interesting alternative for magnetic actuators or artificial muscles.

Figure 1: Photo of the as prepared homogeneous magnetic hydrogel (left). Upon the application of an external magnetic field the polymer can contract or elongate making it appropriate in application such as for magnetic actuator or even artificial muscles (right).