Anisotropic nanocomposite hydrogels with enhanced actuating performance through aligned polymer networks

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  • ReceivedNov 15, 2019
  • AcceptedDec 18, 2019
  • PublishedJan 18, 2020



This work was financially supported by the National Key R&D Program of China(2017YFA0207800)

the National Natural Science Foundation of China(KZ75006801)

the National Natural Science Funds for Distinguished Young Scholars(21725401)

the 111 Project(B14009)

and Beijing Technology and Business University 2019 postgraduate research capacity improvement plan.


This work was financially supported by the National Key R&D Program of China (2017YFA0207800), the National Natural Science Foundation of China (KZ75006801), the National Natural Science Funds for Distinguished Young Scholars (21725401), the 111 Project (B14009), and Beijing Technology and Business University 2019 postgraduate research capacity improvement plan.

Interest statement

The authors declare that they have no conflict of interest.

Contributions statement

Tang P, Chen L, Li S and Liu M designed the project. Tang P and Yan H analyzed the results. Tang P, Yan H, Li S and Liu M wrote the paper. All authors contributed to the general discussion of the article.

Author information

Ping Tang is currently a master student at Bei-jing Technology and Business University (BTBU). She received her BSc degree in Beijing Institute of Fashion Technology in 2015. Her current research interests focus on the applications of bioinspired gel materials.

Hao Yan is now a postdoctoral fellow in Prof. Mingjie Liu’s group at Beihang University. In 2006, he joined Professor Zhong Zhang’s research team and received his PhD from the National Center for Nanoscience and Technology, Chinese Academy of Sciences in 2011. After that, he worked at Sinopec Beijing Research Institute of Chemical Industry from 2011 to 2018. His current research interests focus on bioinspired surface and hydrogel actuator designs.

Shuhong Li joined BTBU in 2005 and now he is a professor at BTBU. He received his PhD degree from the Institute of Chemistry, Chinese Academic Sciences in 2003 under the supervision of Prof. Lei Jiang. He carried out his postdoctoral research in an ERATO project of Japan Science and Technology corporation and in Prof. Benzhong Tang’s group at the Hong Kong University of Science and Technology, respectively. His research is mainly on the development and exploration of functional molecules/materials and their advanced properties.

Mingjie Liu is currently a full-time professor at Beihang University. In 2005, he joined Prof. Lei Jiang’s group and received his PhD degree from the National Center for Nanoscience and Technology, Chinese Academy of Sciences (2010). He then worked as a postdoctor in Prof. Takuzo Aida’s group in Riken in Japan from 2010 to 2015. In 2015, he was awarded the “1000 Youth Plan program” and joined Beihang University. In 2017, he was awarded the National Natural Science Funds for Distinguished Young Scholars. His current research interests focus on anisotropic soft matter with ordered structures, bioinspired design, and application of gel materials.

Supplementary data

Supplementary information

Experimental details and supporting data are available in the online version of the paper.


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  • Figure 1

    (a) Schematic description of the anisotropic hydrogel. NIPAM, SA, CNTs, covalent crosslinkers (BIS) for NIPAM, and ionic crosslinkers (calcium chloride) for SA. (b) (i) FESEM image of the fractured PNIPAM/CA (I) hydrogel; (ii, iii) polarized microscope images of the PNIPAM/CA (I) hydrogel; (c) (i) FESEM image of the fractured PNIPAM/CA (A) hydrogels; (ii, iii) polarized microscope images of the PNIPAM/CA (A) hydrogel; (d) 2D SAXS images of CNTs-PNIPAM/CA (I) and CNTs-PNIPAM/CA (A) hydrogels.

  • Figure 2

    The mechanical properties of the hydrogels. (a) Schematic representation for the mechanical tests of the samples; (b) tensile strain-stress curves of CNTs-PNIPAM/CA (I) hydrogel (yellow line) and CNTs-PNIPAM/CA (A) hydrogel (red line for the parallel direction, blue line for the perpendicular direction); (c) the tensile strengths of hydrogels with different concentrations of CNTs.

  • Figure 3

    Thermo-responsive behavior of the hydrogels. (a) (i) Schematic representation and pictures of CNTs-PNIPAM/CA (I) hydrogel (CNTs, 0.12 wt.%); (ii–v) pictures of CNTs-PNIPAM/CA (I) hydrogel and plots showing the changes in the relative length (Lt/L0 (%)). (b) (i) Schematic representation and pictures of CNTs-PNIPAM/CA (A) hydrogel; (ii–v) pictures of CNTs-PNIPAM/CA (A) hydrogel and plots showing the changes in the relative length (Lt/L0 (%)). (c) Plots showing changes in the relative weight of hydrogels (Δw/w0 (%)) vs. time. (d) Reversibility of CNTs-PNIPAM/CA (A) hydrogel. L0 is the original length of hydrogels, Lt is the length of the contracted hydrogels. Δw=w0wt, w0 is the original weight of hydrogels, and wt is the weight of the contracted hydrogels.

  • Figure 4

    Actuation of hydrogels. Pictures of the lifting weight by NIR: (a) mw=0.1 g, mH=1 g, ΔL/L0=40%; (b) mw=0.03 g, mH=3 g, ΔL/L0=20%. Contraction strain=ΔL/L0 (%), ΔL=L0Lt, L0 is the original length of the hydrogel, and Lt is the length of the contracted hydrogel. Actuations of Bi-0° (c) and Bi-45° (d) in water at 80°C.


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