Swelling-Driven Shaping of Thermally Responsive Photo-Patterned Gel Sheets

ORAL

Abstract

Swelling-mediated shaping of patterned non-Euclidean plates offers a powerful route to design and engineer complex 3-D structures, with possible applications in biomedicine, robotics, and tunable micro-optics. We have studied the behavior of poly(N-isopropyl acrylamide) (PNIPAm) copolymers containing pendent benzophenone units that allow the degree of crosslinking to be tuned by varying the dose of ultraviolet light. A halftone (gray) gel lithography approach, wherein two photomasks enable patterning of highly-crosslinked domains within a lightly-crosslinked matrix, is shown to provide effectively continuous variations in swelling in truly two-dimensional patterns. We show how this technique can be harnessed to form complex, reversibly actuating, 3-D structures through patterned growth.

Authors

  • Myunghwan Byun

    • Polymer Science and Engineering Department, University of Massachusetts Amherst
    • University of Massachusetts Amherst
  • Jungwook Kim

    • Polymer Science and Engineering Department, University of Massachusetts Amherst
  • Ryan Hayward

    • University of Massachusetts Amherst
    • Polymer Science and Engineering Department, University of Massachusetts Amherst
    • University of Massachusetts
    • UMass - Amherst Polymer Science and Engineering
    • University of Massachusetts Amhesrt
    • Polymer Science and Engineering Department at UMass-Amherst
    • University of Massachusetts - Amherst
    • Polymer Science and Engineering Department at University of Massachusetts Amherst
  • James Hanna

    • Physics Department, University of Massachusetts Amherst
    • Department of Physics, University of Massachusetts - Amherst
  • Christian Santangelo

    • Physics Department, University of Massachusetts Amherst