3D Printing of Thermoplastic‐Bonded Soft‐ and Hard‐Magnetic Composites: Magnetically Tuneable Architectures and Functional Devices

Abstract

Magnetic materials are key players for the development and implementation of novel technologies. However, the integration and tunability of these materials in complex designs remain challenging due to constraints in currently available manufacturing approaches. Herein, the fabrication of 3D printing (3DP) thermoplastic‐bonded magnetic composites is investigated with both tailored geometries and magnetic properties using a customized fused deposition modeling 3D printer. First, the level of complexity that can be achieved by printing magnetic architectures with different geometries is shown. Next, it is shown that architectures with tailored magnetic properties (saturation magnetization and coercivity) can be achieved by combining prints with different magnetic properties (i.e., hard‐ and soft, or hard‐ and semi‐hard). Additionally, to demonstrate the versatility and powerfulness of fused deposition, self‐contained mechanisms, which comprise multiple parts (magnetic and nonmagnetic) without the need for assembly, are successfully fabricated. As an example, planetary magnetic gearboxes are printed with different configurations and their potential applicability as magnetic rotary encoders is demonstrated.

Magnetic Soft Materials and Robots

“…Recent advances in additive manufacturing for soft materials have accelerated progress in the design and fabrication of magnetic soft materials and robots with more complex shapes and more sophisticated actuation and functions. Widely used additive manufacturing techniques such as extrusion-based 3D printing (e.g., direct ink writing ,− and fused deposition modeling , ) and light-based 3D printing − have been adopted for fabricating different types of magnetic soft materials and robots (Figure b,c and Table ).…”

Magnetic Actuation Systems for Miniature Robots: A Review

“…As the most straightforward strategy, dragging microrobots with the propulsive force resulting from a field gradient are proposed . Inspired by biological microorganisms, torque‐driven swimming microrobots are developed, such as screw‐like microrobots mimicking bacteria and flexible oar‐like microrobots imitating spermatozoa . These two types of robots can realize 3D locomotion.…”

Magnetically Controlled Soft Robotics Utilizing Elastomers and Gels in Actuation: A Review

“…[ 88 ] Pané and coworkers printed and bonded domains filled with soft and hard magnetic particles to find an optimal balance between the reversibility of soft magnetic domains and the rapid actuation ability of hard magnetic domains. [ 89 ] Nuzzo and coworkers harnessed multimaterial printability to its full potential to fabricate magnetically steered jellyfish‐ and starfish‐like aquatic soft robots made of ionic hydrogels. [ 90 ] The structures were printed in planar shapes, and subsequent hydration with preprogrammed amount of salt content resulted in fully 3D structures with locally varying volumes in a deterministic manner; this spatiotemporally controlled fabrication method is an epitome of 4D printing.…”