Research ArticleAPPLIED SCIENCES AND ENGINEERING

Programming a crystalline shape memory polymer network with thermo- and photo-reversible bonds toward a single-component soft robot

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Science Advances  26 Jan 2018:
Vol. 4, no. 1, eaao3865
DOI: 10.1126/sciadv.aao3865
  • Fig. 1 Network polymer synthesis and programmed shape-morphing mechanisms.

    (A) Synthetic route for the polyurethane network. (B) Thermally induced transesterification and transcarbamoylation and photo-reversible dimerization of nitro-cinnamate. (C) Mechanisms for permanent shape reconfiguration via solid-state thermal plasticity. (D) Reversible actuation via photo-defined reversible shape memory behavior. Scale bars, 1 cm.

  • Fig. 2 Quantitative evaluation of the photo-defined reversible actuation.

    (A) Impact of irradiation time and Rc on the actuation strain (prestretch strain is maintained constant at 400%). (B) Dependence of actuation strain on prestretch strain (Rc, 0.47; irradiation time, 120 s). (C) Cyclic actuation at the maximum actuation strain of 40% (Rc, 0.47; irradiation time, 120 s; prestretch strain, 400%). (D) Visual demonstration of the maximum reversible actuation strain of 40% (photo-irradiated active regions are marked in red for better visualization).

  • Fig. 3 Demonstration of shape-morphing behaviors via photo-defined reversible actuation and thermally triggered permanent shape reconfiguration.

    (A) Various nonlinear motions realized by localized photo-irradiation. (The white and black colors in the masks denote exposed and unexposed areas, respectively.) (B) Sequential programming process of a 3D flower. Green areas represent active regions. (C) Stress relaxation curve and construction of a 3D shape via the corresponding solid-state plasticity. (D) Spatio-selective actuation in a 3D structure. (i) Selective angular actuation. (ii) No actuation for comparison. Scale bars, 1 cm.

  • Fig. 4 Single-component O-Unibots.

    (A) Fabrication and reversible actuation of the O-Unibots. (B) Finite element simulation of reversible flapping 3D crane. (C) Deployment of the O-Unibot via one-way shape memory effect, showing that it cannot enter in the original form but can pass through in the compact temporary form and then deploy back to the robotic form. Scale bars, 1 cm.

Supplementary Materials

  • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/4/1/eaao3865/DC1

    fig. S1. 1H NMR spectra of the polymer precursors.

    fig. S2. Differential scanning calorimeter curve of the polyurethane network.

    fig. S3. Cyclic photo-programming and photo-erasing performance.

    fig. S4. Scheme for spatio-selective photo-defining reversible actuation onto a 3D shape.

    table S1. Photo-programming parameters for locally defined reversible shape memory materials (white area represents the exposed area of the sample).

    movie S1. Cyclic reversible actuation of the 3D crane (accelerated by 15).

  • Supplementary Materials

    This PDF file includes:

    • fig. S1. 1H NMR spectra of the polymer precursors.
    • fig. S2. Differential scanning calorimeter curve of the polyurethane network.
    • fig. S3. Cyclic photo-programming and photo-erasing performance.
    • fig. S4. Scheme for spatio-selective photo-defining reversible actuation onto a 3D shape.
    • table S1. Photo-programming parameters for locally defined reversible shape memory materials (white area represents the exposed area of the sample).

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    Other Supplementary Material for this manuscript includes the following:

    • movie S1 (.mp4 format). Cyclic reversible actuation of the 3D crane (accelerated by 15).

    Files in this Data Supplement:

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