• 文献标题:   Spontaneous Alignment of Graphene Oxide in Hydrogel during 3D Printing for Multistimuli-Responsive Actuation
  • 文献类型:   Article
  • 作  者:   ZHANG MC, WANG YL, JIAN MQ, WANG CY, LIANG XP, NIU JL, ZHANG YY
  • 作者关键词:   anisotropic composite, directinkwriting, graphene oxide, multistimuli response, shapemorphing
  • 出版物名称:   ADVANCED SCIENCE
  • ISSN:  
  • 通讯作者地址:   Tsinghua Univ
  • 被引频次:   3
  • DOI:   10.1002/advs.201903048 EA JAN 2020
  • 出版年:   2020

▎ 摘  要

Natural materials are often compositionally and structurally heterogeneous for realizing particular functions. Inspired by nature, researchers have designed hybrid materials that possess properties beyond each of the components. Particularly, it remains a great challenge to realize site-specific anisotropy, which widely exists in natural materials and is responsible for unique mechanical properties as well as physiological behaviors. Herein, the spontaneous formation of aligned graphene oxide (GO) flakes in sodium alginate (SA) matrix with locally controlled orientation via a direct-ink-writing printing process is reported. The GO flakes are spontaneously aligned in the SA matrix by shear force when being extruded and then arranged horizontally after drying on the substrate, forming a brick-and-mortar structure that could anisotropically contract or expand upon activation by heat, light, or water. By designing the printing pathways directed by finite element analysis, the orientation of GO flakes in the composite is locally controlled, which could further guide the composite to transform into versatile architectures. Particularly, the transformation is reversible when water vapor is applied as one of the stimuli. As a proof of concept, complex morphing architectures are experimentally demonstrated, which are in good consistency with the simulation results.