Extrusion Freeform Fabrication of Bone-Like Mineralized Hydrogels and Muscle-like Actuators

Extrusion freeform fabrication has been used to build shapes from agarose, polyacrylamide and polyacrylic acid hydrogels. Contraction and bending can be induced by pH change or application ofa voltage between embedded electrodes. Mineral reinforcement can be induced by incorporating salts into the gels and allowing them to react.