Electro and magnetoactive printed bi-functional actuators based on alginate hybrid hydrogels.

Soft materials are attracting much attention for the development of biostructures able to mimic the movement of natural systems by remote actuation. Multi-sensitive hydrogels are among the best materials for obtaining dynamic and biocompatible soft structures for soft actuators and related biomedical devices. Nevertheless, bioinks based on naturally occurring and stimuli responsive hydrogels able to be 3D printed continues being a challenge for advanced applications. In this work 3D printable electrically and magnetically responsive, non-cytotoxic, hybrid hydrogels based on alginate and zero monovalent iron nanoparticles (NPs) are presented. The effect of NPs addition on the physico-chemical properties of the hydrogels is addressed, together with its effect on the functional electroactive and magnetoactive response. NPs concentration up to 10 % do not affect the mechanical stability of the gels, while promoting an increase actuation response.