Research ArticleAPPLIED SCIENCES AND ENGINEERING

Photothermally and magnetically controlled reconfiguration of polymer composites for soft robotics

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Science Advances  02 Aug 2019:
Vol. 5, no. 8, eaaw2897
DOI: 10.1126/sciadv.aaw2897
  • Fig. 1 Shape memory cantilever containing chained magnetic particles.

    (A) Actuation and (B and C) simulations of a DiAPLEX cantilever film containing chained magnetic particles. The permanent magnet (∇H) and LED are indicated in the top left panel. (B) The contours show the degree of actuation (0, flat; 1, contacting magnet) of a simulated filament across a range of positions and temperatures. (C) Simulated still images correspond to discrete points along the path indicated in (B), at a distance of 2.3 cm from the magnet, which is consistent with the experimental geometry on the left. See movies S1 and S2 for experiments and simulations of the cantilever. Photo credit: Jessica A.-C. Liu, North Carolina State University.

  • Fig. 2 Rotation of a shape memory flower while pulsing the LED.

    Rotation of a DiAPLEX flower with six petals containing unchained magnetic particles counterclockwise beneath the LED first causes photothermal heating and softening of the petals, followed by lifting beneath the permanent magnet. Switching the LED on and off allows heating and lifting of every other petal. A video of this experiment is presented in movie S4. Photo credit: Jessica A.-C. Liu, North Carolina State University.

  • Fig. 3 Magnetic scrolls.

    (A) Actuation of an IROGRAN scroll by moving the magnet toward the scroll and pulling the scroll open. The scroll abruptly closes when the magnet is pulled further away. (B) Actuation of a DiAPLEX scroll placed next to a permanent magnet with illumination by a LED. Turning off the LED and removing the magnet locks the open configuration. Removing the magnet and turning on the LED causes the scroll to close. Videos for these experiments are presented in movies S5 and S6. Photo credit: Jessica A.-C. Liu, North Carolina State University.

  • Fig. 4 Unbiased and biased elastomer snappers.

    (A) An unbiased IROGRAN snapper containing magnetic particles chained along its length is placed between two permanent magnets. When moving the frame supporting the snapper closer to one magnet or the other, snapping occurs to pull the buckled direction toward the magnet. Moving the sample to the left and right causes repeated, reversible snapping. (B) Biased IROGRAN snapper containing magnetic particles chained along its length. Moving the frame closer to the magnet causes snapping toward the magnet. When moving the frame away from the magnet, snapping occurs away from the magnet and back into the favored direction set by biasing. The simulations closely match experiments, and videos are presented in movies S7 to S10. Photo credit: Jessica A.-C. Liu, North Carolina State University.

  • Fig. 5 Unbiased and biased shape memory snappers.

    Actuation of DiAPLEX snappers containing chained magnetic particles with Camera 1 and Camera 2 positioned on both sides of the snapper. Camera 1 and Camera 2 show the sides with the permanent magnet and LED, respectively. Placement of the cameras and the snapper is shown in fig. S6A. (A) The unbiased snapper has a flat permanent shape. Turning on the LED triggers snapping toward the magnet, which is repeated when the sample is turned around. (B) The permanent shape of the biased snapper is buckled toward the LED. (C) Summary of simulations for a biased snapper, where the contour lines (drawn at 0.5% intervals) indicate the dependence of the degree of snapping on temperature and the distance from the magnet. The same plot for an unbiased snapper is presented in fig. S7. (D) Simulations of the biased snapper correlate well with experimental observations. The simulations closely match experiments, and videos are presented in movies S11 to S14. Photo credit: Jessica A.-C. Liu, North Carolina State University.

  • Fig. 6 Shape memory grabber picking up, transporting, and releasing small objects.

    (A) Blueberries (~1.5 g) using the magnet-assisted method (movie S15) and (B) cherry tomatoes (~3.2 g) using the push-through method (movie S16). The mass of the grabber is 152 mg. Photo credit: Jessica A.-C. Liu, North Carolina State University.

Supplementary Materials

  • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/5/8/eaaw2897/DC1

    Supplementary Materials and Methods

    Fig. S1. Magnetization curves of loaded IROGRAN and DiAPLEX films.

    Fig. S2. Scanning electron microscopy and optical extinction spectra of loaded DiAPLEX films.

    Fig. S3. Chemical and mechanical analysis of loaded and unloaded polymer films.

    Fig. S4. Experimental setup for thermal imaging of cantilever.

    Fig. S5. DiAPLEX flower with eight petals containing unchained magnetic particles.

    Fig. S6. Experimental setup for preparation and imaging of DiAPLEX snappers.

    Fig. S7. Summary of simulations for an unbiased DiAPLEX snapper.

    Fig. S8. Graphical representation of the net force acting on an arbitrary segment of the filament.

    Fig. S9. Geometry of a cantilever-type SMP with constant curvature.

    Fig. S10. Quality of actuation for a DiAPLEX cantilever as a function of magnetic field and field gradient.

    Movie S1. Cantilever experiment.

    Movie S2. Cantilever simulation.

    Movie S3. Cycling of cantilever experiment.

    Movie S4. Flower.

    Movie S5. IROGRAN scroll.

    Movie S6. DiAPLEX scroll.

    Movie S7. Unbiased IROGRAN snapper experiment.

    Movie S8. Unbiased IROGRAN snapper simulation.

    Movie S9. Biased IROGRAN snapper experiment.

    Movie S10. Biased IROGRAN snapper simulation.

    Movie S11. Unbiased DiAPLEX snapper experiment.

    Movie S12. Unbiased DiAPLEX snapper simulation.

    Movie S13. Biased DiAPLEX snapper experiment.

    Movie S14. Biased DiAPLEX snapper simulation.

    Movie S15. Magnet-assisted grabber.

    Movie S16. Push-through grabber.

    Movie S17. Five cantilevers with elastic modulus offset by 10°C.

  • Supplementary Materials

    The PDF file includes:

    • Supplementary Materials and Methods
    • Fig. S1. Magnetization curves of loaded IROGRAN and DiAPLEX films.
    • Fig. S2. Scanning electron microscopy and optical extinction spectra of loaded DiAPLEX films.
    • Fig. S3. Chemical and mechanical analysis of loaded and unloaded polymer films.
    • Fig. S4. Experimental setup for thermal imaging of cantilever.
    • Fig. S5. DiAPLEX flower with eight petals containing unchained magnetic particles.
    • Fig. S6. Experimental setup for preparation and imaging of DiAPLEX snappers.
    • Fig. S7. Summary of simulations for an unbiased DiAPLEX snapper.
    • Fig. S8. Graphical representation of the net force acting on an arbitrary segment of the filament.
    • Fig. S9. Geometry of a cantilever-type SMP with constant curvature.
    • Fig. S10. Quality of actuation for a DiAPLEX cantilever as a function of magnetic field and field gradient.

    Download PDF

    Other Supplementary Material for this manuscript includes the following:

    • Movie S1 (.mp4 format). Cantilever experiment.
    • Movie S2 (.mp4 format). Cantilever simulation.
    • Movie S3 (.mp4 format). Cycling of cantilever experiment.
    • Movie S4 (.mp4 format). Flower.
    • Movie S5 (.mp4 format). IROGRAN scroll.
    • Movie S6 (.mp4 format). DiAPLEX scroll.
    • Movie S7 (.mp4 format). Unbiased IROGRAN snapper experiment.
    • Movie S8 (.mp4 format). Unbiased IROGRAN snapper simulation.
    • Movie S9 (.mp4 format). Biased IROGRAN snapper experiment.
    • Movie S10 (.mp4 format). Biased IROGRAN snapper simulation.
    • Movie S11 (.mp4 format). Unbiased DiAPLEX snapper experiment.
    • Movie S12 (.mp4 format). Unbiased DiAPLEX snapper simulation.
    • Movie S13 (.mp4 format). Biased DiAPLEX snapper experiment.
    • Movie S14 (.mp4 format). Biased DiAPLEX snapper simulation.
    • Movie S15 (.mp4 format). Magnet-assisted grabber.
    • Movie S16 (.mp4 format). Push-through grabber.
    • Movie S17 (.mp4 format). Five cantilevers with elastic modulus offset by 10°C.

    Files in this Data Supplement:

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