Correlation Between Microscale Magnetic Particle Distribution and Magnetic-Field-Responsive Performance of Three-Dimensional Printed Composites

Abstract

To date, several additive manufacturing (AM) technologies have been developed for fabricating smart particle–polymer composites. Those techniques can control particle distributions to achieve gradient or heterogeneous properties and functions. Such manufacturing capability opened up new applications in many fields. However, it is still widely unknown how to design the localized material distribution to achieve desired product properties and functionalities. The correlation between microscale material distribution and macroscopic composite performance needs to be established. In our previous work, a novel magnetic field-assisted stereolithography (M-PSL) process was developed, for fabricating magnetic particle–polymer composites. In this work, we focused on the study of magnetic-field-responsive particle–polymer composite design with the aim of developing guidelines for predicting the magnetic-field-responsive properties of the composite. Microscale particle distribution parameters, including particle loading fraction, magnetic particle chain structure, microstructure orientation, and particle distribution patterns, were investigated. Their influences on the properties of particle–polymer liquid suspensions and properties of the three-dimensional (3D) printed composites were characterized. By utilizing the magnetic anisotropy properties of the printed composites, motions of the printed parts could be actuated at different positions in the applied magnetic field. Physical models were established to predict magnetic properties of the composite and trigger distance of fabricated parts. The predicted results agreed well with the experimental measurements, indicating the effectiveness of predicting macroscopic composite performance using microscale distribution data, and the feasibility of using the developed physical models to guide multimaterial and multifunctional composite design.

A Fully Three-Dimensional Printed Inchworm-Inspired Soft Robot with Magnetic Actuation

“…M-PSL process is a type of additive manufacturing process that can fabricate particle-polymer composites directly from digital model in a layer by layer manner, with locally controlled magnetic particle distributions. 40 A prototype machine was developed for implementing the fabrication process of particle-polymer composites. In the system, an external magnetic field is used to control particle dispersion and local distribution ratios.…”

3D Printed Biomimetic Soft Robot with Multimodal Locomotion and Multifunctionality

“…In this study, a novel multimaterial 3D printing process, M-SL developed in our previous articles, 54,56,69 is employed to fabricate the proposed multiscale and multimaterial soft robot. This method can fabricate particle/polymer composite structures directly from the digital model, in a layer-by-layer manner.…”

“…Further details of the 3D printing process and experiments can be found in our previous publication. 56,69 As the base material for printing the proposed soft robot, Spot E elastic from Spot A Materials (Sonnaya Ulitka S.L., Barcelona, Spain) was used, which allows the cured polymer to bend easily. 57 EMG 1200 dry magnetic nanoparticles (Ferrotec Corporation, NH) with 10 nm nominal particle diameter was used as the magnetic functional particle filler in the proposed soft robot.…”

“…The gray-scale mask image design is based on the relationship between the gray-scale value and light intensity, as developed in our previous publications. 54,69 After finishing printing a layer, the platform moves up to separate the newly printed layer from the platform and the system continues with the next layer printing until the last layer is finished. The printed soft robot samples are rinsed in alcohol and postcured in an ultraviolet chamber for 20 s to relieve from any remaining residual stress.…”

Air-Diffusion-Channel Constrained Surface Based Stereolithography for Three-Dimensional Printing of Objects With Wide Solid Cross Sections

“…The ultraviolet (UV) light penetrates the transparent constrained surface and cures the liquid polymer. Currently, the two most widely used classes of constrained surfaces are: (1) glass or acrylic plate coated with polydimethylsiloxane (PDMS) [8,[12][13][14][15][16][17][18] and (2) air permeable film that is clamped and tensioned, due to the relatively low cost, ease of fabrication, good oxygen permeability, and excellent optical transparency. The oxygen permeability of constrained surface is critical to the reliability and robustness of the system, and the printable geometries [19].…”