Topology optimization and 3D printing of multimaterial magnetic actuators and displays

Abstract

Upcoming actuation systems will be required to perform multiple tightly coupled functions analogous to their natural counterparts; e.g., the ability to control displacements and high-resolution appearance simultaneously is necessary for mimicking the camouflage seen in cuttlefish. Creating integrated actuation systems is challenging owing to the combined complexity of generating high-dimensional designs and developing multifunctional materials and their associated fabrication processes. Here, we present a complete toolkit consisting of multiobjective topology optimization (for design synthesis) and multimaterial drop-on-demand three-dimensional printing for fabricating complex actuators (>106 design dimensions). The actuators consist of soft and rigid polymers and a magnetic nanoparticle/polymer composite that responds to a magnetic field. The topology optimizer assigns materials for individual voxels (volume elements) while simultaneously optimizing for physical deflection and high-resolution appearance. Unifying a topology optimization-based design strategy with a multimaterial fabrication process enables the creation of complex actuators and provides a promising route toward automated, goal-driven fabrication.

Multifunctional magnetic soft composites: a review

“…For example, by mixing Fe 3 O 4 particles into melted poly-lactic acid (PLA), researchers utilize fused filament fabrication to print PLA-based magnetic SMP filaments into 3D structures with remote-activated shape change under alternating magnetic field ( figure 3(e) [ 96 ]). Recently, a customized inkjet printing system enables the rapid fabrication of multi-material structures with different mechanical, magnetic, and optical properties for designed magnetic actuation [ 112 ].…”

“…The properties and functionalities of the soft material systems are related to the configurations and deformations of the structures. With the ability to undergo large deformations as programmed, the mechanical [ 46 , 80 , 107 , 121 ], optical [ 112 , 122 ], and acoustic properties [ 120 , 123 – 127 ], or wettability [ 106 , 119 ] of magnetic soft composites are actively tunable under the applied magnetic field. For instance, an array of microplates embedded with aligned Fe microparticles possess a superhydrophobic or hydrophilic surface on each side of the plates ( figure 5(d) [ 119 ]).…”

“…An array of dipole elements can modify tilting angles under a relatively small magnetic field, and the configurable structure innovatively demonstrates tunable resonant frequency as an electromagnetic filter [ 128 ]. In recent work, an optimization algorithm is utilized to assign magnetic and non-magnetic polymers with distinct transmissions to different locations, realizing desired actuation and optical appearance under the applied magnetic field [ 112 ].…”

Scientometric Analysis and Systematic Review of Multi-Material Additive Manufacturing of Polymers

“…To improve the printing resolution with a given nozzle density, a complete system integrating multi-objective topology optimization into multi-material MJ printing for fabricating complex 3D parts was developed, as shown in Figure 13 . In this approach, a topology optimizer dispenses material for a single voxel (volume element) while optimizing physical deformation and high-resolution appearance, and multi-material MJ with a 35 μm resolution was finally demonstrated [ 144 ].…”

Printing Multi‐Material Organic Haptic Actuators

“…Another type of polymeric actuator of interest for haptics is a magnetic composite, [64,[82][83][84] in which magnetic particles are embedded in an elastomeric matrix. In response to an external magnetic field, the magnetic domains rotate and generate micro-torque, leading to macroscopic mechanical deformation, as shown in Figure 2e, and magnetic actuators have demonstrated multiple modes of actuation.…”