Swelling-induced deformations: a materials-defined transition from macroscale to microscale deformations

Abstract

Swelling-induced deformations are common in many biological and industrial environments, and the shapes and patterns that emerge can vary across many length scales. Here we present an experimental study of a transition between macroscopic structural bending and microscopic surface creasing in elastomeric beams swollen non-homogeneously with favorable . We show that this transition is dictated by the materials and geometry of the system, and we develop a simple scaling model based on competition between bending and swelling energies that predicts if a given droplet would deform a polymeric structure macroscopically or microscopically. We demonstrate how proper tuning of materials and geometry can generate instabilities at multiple length scales in a single structure.

Swelling-induced and controlled curving in layered gel beams

“…was studied; it was shown that wrinkling of the thin layer is an admissible deformation mode of the system, which did not bend due to the constraints of the substrate. A similar problem can also be found in [20], where bending of a homogeneous beam swollen by a solvent droplet put on the top surface is studied; it was shown that, at equilibrium, the beam recovers the straight initial configuration, whereas, during the transient, bending can only occur if the thickness of the beam is below the so-called elastoswelling length scale. Otherwise, wrinkling of the swollen top surface appears.…”

A finite element implementation of a coupled diffusion-deformation theory for elastomeric gels

“…This example problem is modeled after the recent experiments of Yoon et al (2010) which are similar to the experiments of Holmes and co-workers (Holmes et al, 2011;Pandey and Holmes, 2013). In the experiments of Yoon et al (2010) a thin layer of a swellable gel is bonded to a non-swellable elastomer, the gel is allowed to swell and this causes large bending of the bilayer.…”

“…For example, recently Giner et al (2009) published an ABAQUS implementation of the extended finite element method for linear elastic fracture analysis as a UEL subroutine. Also Park and Paulino (2012) published an ABAQUS implementation of a cohesive finite element as a UEL subroutine. In both cases, for educational purposes, the numerical implementation is discussed in detail, and the source code for the UEL was provided.…”

“…However, in that paper we did not provide any details regarding our numerical implementation procedures and methods. Accordingly, in the spirit of the recent papers by Giner et al (2009) and Park and Paulino (2012), the main purpose of this paper is to discuss the details of the numerical implementation of our coupled diffusion-deformation theory for non-ionic gels, and also to make available the source code for the UEL in ABAQUS.…”

Smoothening creases on surfaces of strain-stiffening materials

“…Creases, however, have been observed routinely on elastic blocks compressed by various means, including mechanical forces Gent and Cho, 1999;Ghatak and Das, 2007;Mora et al, 2011), constrained swelling (Arifuzzaman et al, 2012;Barros et al, 2012;Dervaux and Ben Amar, 2012;Dervaux et al, 2011;Guvendiren et al, 2010;Ortiz et al, 2010;Pandey and Holmes, 2013;Tanaka, 1986;Tanaka et al, 1987;Trujillo et al, 2008;Weiss et al, 2013;Zalachas et al, 2013), temperature change , electric fields (Park et al, 2013;Wang et al, 2012;Wang et al, 2011;Wang and Zhao, 2013a;Xu and Hayward, 2013), and light (Yoon et al, 2012). Creases have been studied in soft tissues (Bayly et al, 2014;Jin et al, 2011;Yang et al, 2007).…”