3D-printed Magnetic Elastomers: Effects of Hybrid Magnetic Content on the Complex Actuation of Elastomers

3D-printed magnetic elastomers are smart materials that display remotely controllable and consistent deformation by integrating soft and hard magnetic particulate into a flexible polymer matrix, with applications in biomedical engineering, soft robotics, dampeners, and magnetic actuators. Typically, soft magnets allow for a greater degree of deformation, while hard magnets allow for greater control over the type of deformation. This research focused on comparing the complex motion of elastomers containing various combinations of hard and soft magnetic particulate in order to utilize the best properties of both. Using Strontium Ferrite (SrFe) as the hard magnet and Carbonyl Iron (Fe) as the soft magnet, four combinations of SrFe/Fe magnetic particulate by volume % were created: 15% SrFe, 0% Fe // 10% SrFe, 5% Fe // 5% SrFe, 10% Fe // 0% SrFe, 15% Fe. Samples of each combination were placed in a transverse applied magnetic field and tested under increasing field strengths up to 0.15 Tesla. The amount of physical deflection and rotation exhibited by the elastomers was visually recorded. The images were analyzed using a MATLAB program, outputting numerical degrees of deformation that allowed for precise comparison. Analysis revealed that the combination samples containing 10 vol% SrFe, 5 vol% Fe both deflected and rotated to the greatest degree and with the most control. This study showcases adjustable magnetoactive properties by integrating different combinations of hard and soft magnetic particulate.