Jožef Stefan Institute, Solid State Physics Department, Jamova cesta 39, 1000, Ljubljana, Slovenia.
On leave from: Ioffe Institute, Division of Physics of Dielectrics and Semiconductors, Politekhnicheskaya 26, 194021, St. Petersburg, Russia.
Nat Commun. 2023 Feb 10;14(1):764. doi: 10.1038/s41467-023-36426-y.
The current development of soft shape-memory materials often results in materials that are typically limited to the synthesis of thin-walled specimens and usually rely on complex, low-yield manufacturing techniques to fabricate macro-sized, solid three-dimensional objects. However, such geometrical limitations and slow production rates can significantly hinder their practical implementation. In this work, we demonstrate a shape-memory composite material that can be effortlessly molded into arbitrary shapes or sizes. The composite material is made from main-chain liquid crystal elastomer (MC-LCE) microparticles dispersed in a silicone polymer matrix. Shape-programmability is achieved via low-temperature induced glassiness and hardening of MC-LCE inclusions, which effectively freezes-in any mechanically instilled deformations. Once thermally reset, the composite returns to its initial shape and can be shape-programmed again. Magnetically aligning MC-LCE microparticles prior to curing allows the shape-programmed artefacts to be additionally thermomechanically functionalized. Therefore, our material enables efficient morphing among the virgin, thermally-programmed, and thermomechanically-controlled shapes.
目前软形状记忆材料的发展通常导致材料仅限于薄壁试样的合成,并且通常依赖于复杂的、低产量的制造技术来制造宏观的、固态的三维物体。然而,这种几何限制和缓慢的生产速度会严重阻碍它们的实际应用。在这项工作中,我们展示了一种形状记忆复合材料,可以毫不费力地模制成任意形状或尺寸。该复合材料由主链液晶弹性体(MC-LCE)微粒分散在硅酮聚合物基质中制成。通过低温诱导的 MC-LCE 内含物的玻璃化和硬化来实现形状可编程性,这有效地冻结了任何机械注入的变形。一旦热重置,复合材料将恢复到其初始形状,并可以再次进行形状编程。在固化之前对 MC-LCE 微粒进行磁定向,允许对形状编程的制品进行额外的热机械功能化。因此,我们的材料可以实现原始形状、热编程形状和热机械控制形状之间的高效变形。