Soft Multimaterial Magnetic Fibers and Textiles

Abstract

Magnetically responsive soft materials are promising building blocks for the next generation of soft robotics, prosthesis, surgical tools, and smart textiles. To date, however, the fabrication of highly integrated magnetic fibers with extreme aspect ratios, that can be used as steerable catheters, endoscopes, or within functional textiles remains challenging. Here, multimaterial thermal drawing is proposed as a material and processing platform to realize 10s of meters long soft, ultrastretchable, yet highly resilient magnetic fibers. Fibers with a diameter as low as 300 µm and an aspect ratio of 10⁵ are demonstrated, integrating nanocomposite domains with ferromagnetic microparticles embedded in a soft elastomeric matrix. With the proper choice of filler content that must strike the right balance between magnetization density and mechanical stiffness, fibers withstanding strains of >1000% are shown, which can be magnetically actuated and lift up to 370 times their own weight. Magnetic fibers can also integrate other functionalities like microfluidic channels, and be weaved into conventional textiles. It is shown that the novel magnetic textiles can be washed and sustain extreme mechanical constraints, as well as be folded into arbitrary shapes when magnetically actuated, paving the way toward novel intriguing opportunities in medical textiles and soft magnetic systems.

Keywords: magnetic polymer composites; multimaterial fibers; smart textiles; soft actuators; soft materials.