다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Soft materials capable of transforming between three-dimensional (3D) shapes in response to stimuli such as light, heat, solvent, electric and magnetic fields have applications in diverse areas such as flexible electronics1,2, soft robotics3,4 and biomedicine5–7. In particular, magnetic fields offer a safe and effective manipulation method for biomedical applications, which typically require remote actuation in enclosed and confined spaces8–10. With advances in magnetic field control
 11
 , magnetically responsive soft materials have also evolved from embedding discrete magnets
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 or incorporating magnetic particles
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 into soft compounds to generating nonuniform magnetization profiles in polymeric sheets14,15. Here we report 3D printing of programmed ferromagnetic domains in soft materials that enable fast transformations between complex 3D shapes via magnetic actuation. Our approach is based on direct ink writing
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 of an elastomer composite containing ferromagnetic microparticles. By applying a magnetic field to the dispensing nozzle while printing
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 , we reorient particles along the applied field to impart patterned magnetic polarity to printed filaments. This method allows us to program ferromagnetic domains in complex 3D-printed soft materials, enabling a set of previously inaccessible modes of transformation, such as remotely controlled auxetic behaviours of mechanical metamaterials with negative Poisson’s ratios. The actuation speed and power density of our printed soft materials with programmed ferromagnetic domains are orders of magnitude greater than existing 3D-printed active materials. We further demonstrate diverse functions derived from complex shape changes, including reconfigurable soft electronics, a mechanical metamaterial that can jump and a soft robot that crawls, rolls, catches fast-moving objects and transports a pharmaceutical dose.

Printing ferromagnetic domains for untethered fast-transforming soft materials

Light- and ink-based three-dimensional (3D) printing methods allow the rapid design and fabrication of materials without the need for expensive tooling, dies or lithographic masks. They have led to an era of manufacturing in which computers can control the fabrication of soft matter that has tunable mechanical, electrical and other functional properties. The expanding range of printable materials, coupled with the ability to programmably control their composition and architecture across various length scales, is driving innovation in myriad applications. This is illustrated by examples of biologically inspired composites, shape-morphing systems, soft sensors and robotics that only additive manufacturing can produce.

Printing soft matter in three dimensions

https://pubs.rsc.org/en/content/articlepdf/2017/PY/C6PY01585A

Stimuli-responsive polymers and their applications

A review of 4D printing

The integration of emerging technologies into a complete digital thread promises to disrupt design and manufacturing workflows throughout the value chain to enable efficiency and productivity transformation, while unlocking completely new design freedom. A particularly appealing aspect involves the simultaneous design and manufacture of the macroscale structural topology and material microstructure of a product. Here we demonstrate such a workflow that digitally integrates: design automation – conception and automation of a design problem based on multiscale topology optimization; material compilation – computational geometry algorithms that create spatially-variable, physically-realizable multimaterial microstructures; and digital fabrication – fabrication of multiscale optimized components via voxel-based additive manufacturing with material jetting of multiple photo-curable polymers. We validate the digital design and manufacturing workflow by designing, fabricating, and testing a series of structures that illustrate capabilities, show how it empowers the exploitation of new design freedom, and even challenges traditional design principles relating form, structure, and function.

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Zhen Ding

Papers

Simultaneous Digital Design and Additive Manufacture of Structures and Materials