Stimuli-Responsive Polymer Nanocomposites Inspired by the Sea Cucumber Dermis
Jeffrey R. Capadona,1,2,3
Kadhiravan Shanmuganathan,1
Dustin J. Tyler,2,3
Stuart J. Rowan,1,2,3,4*
Christoph Weder1,2,4*
Sea cucumbers, like other echinoderms, have the ability to rapidly and reversibly alter the stiffness of their inner dermis. It has been proposed that the modulus of this tissue is controlled by regulating the interactions among collagen fibrils, which reinforce a low-modulus matrix. We report on a family of polymer nanocomposites, which mimic this architecture and display similar chemoresponsive mechanic adaptability. Materials based on a rubbery host polymer and rigid cellulose nanofibers exhibit a reversible reduction by a factor of 40 of the tensile modulus, for example, from 800 to 20 megapascals (MPa), upon exposure to a chemical regulator that mediates nanofiber interactions. Using a host polymer with a thermal transition in the regime of interest, we demonstrated even larger modulus changes (4200 to 1.6 MPa) upon exposure to emulated physiological conditions.
1 Department of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, OH 44106, USA.
2 Rehabilitation Research and Development, Louis Stokes Cleveland DVA Medical Center, 10701 East Boulevard, Cleveland, OH 44106, USA.
3 Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA.
4 Department of Chemistry, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA.
* To whom correspondence should be addressed. E-mail: christoph.weder{at}case.edu (C.W.); stuart.rowan{at}case.edu (S.J.R.)
