Actuating shape change in hydrogels via "Extreme Thermodynamics"

ORAL

Abstract

“Extreme Mechanics” often refers to exploiting mechanical instabilities to achieve large shape deformations. An example is provided by the swelling of patterned hydrogels. Here, we consider an alternative mechanism in which a thermodynamic instability or phase transition plays the operative role, actuating similarly large shape changes in an unpatterned hydrogel. This example of “Extreme Thermodynamics” consists of rapidly heating a swollen hydrogel torus through a first-order phase transition to its de-swollen phase. The resulting phase coexistence is characterized by large internal stresses that deform the gel and induce buckling. We will present both our experimental results and a theory qualitatively accounting for our observations.

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Presenters

  • Alberto Fernandez-Nieves

    • Georgia Institute of Technology
    • Physics, Georgia Inst of Tech
    • School of Physics, Georgia Institute of Technology

Authors

  • Alberto Fernandez-Nieves

    • Georgia Institute of Technology
    • Physics, Georgia Inst of Tech
    • School of Physics, Georgia Institute of Technology

  • Ya-Wen Chang

    • Department of Chemical Engineering, Texas Tech University

  • Michael Dimitriyev

    • Georgia Inst of Tech
    • School of Physics, Georgia Institute of Technology

  • Anton Souslov

    • The James Franck Institute and Department of Physics, University of Chicago
    • James Franck Institute, University of Chicago

  • Svetoslav Nikolov

    • School of Mechanical Engineering, Georgia Institute of Technology

  • Alexander Alexeev

    • School of Mechanical Engineering, Georgia Institute of Technology

  • Paul Goldbart

    • School of Physics, Georgia Institute of Technology