Nature Inspired Shape Shifting Soft Magnetic Materials: Inspiration, Fabrication, Mechanism, and Application

Bio-inspired magnetically active shape morphing soft actuators are gaining popularity due to their fast response, remote controllability, wide field of compatibility, and large-scale penetration range in various conditions. Magnetic soft actuators exhibit a reversible change in shape and size when kept under the influence of the magnetic field. The change in their shape and size in the magnetic field is significantly large and fast compared to the other stimuli active actuators. These magnetic soft actuators comprise of a soft polymer matrix and magnetic particles as fillers. Actuators with soft magnetic particles programmed with different shapes are prepared and analyzed under a high-magnification microscope to understand the orientation configuration of the micro-Carbonyl Iron (CI) particles, which are responsible for shape generation. The configuration pattern of CI particle chains in programmed shape is then mimicked using thin iron needles with a high aspect ratio of 1:8 to 1:10 in a silicon matrix. Due to the magnetostriction effect in iron needles, it is possible to control the shape of the soft actuators just by controlling the orientation and alignment of these iron needles. The fabricated soft actuator is then tested for reversible shape change in the magnetic field and the effect of the magnetic field on the amount of deformation or actuation. Further, a soft gripper and a soft locomoting robot are prepared to investigate the motion generated by the shape change.