A comprehensive review of select smart polymeric and gel actuators for soft mechatronics and robotics applications: fundamentals, freeform fabrication, and motion control

Smart polymeric and gel actuators change shape or size in response to stimuli like electricity, heat, or light. These smart polymeric-and gel-based actuators are compliant and well suited for development of soft mechatronic and robotic devices. This paper provides a thorough review of select smart polymeric and gel actuator materials where an automated and freeform fabrication process, like 3D printing, is exploited to create custom shaped monolithic devices. In particular, the advantages and limitations, examples of applications, manufacturing and fabrication techniques, and methods for actuator control are discussed. Finally, a rigorous comparison and analysis of some of the advantages and limitations, as well as manufacturing processes, for these materials, are presented.