Swelling-induced wrinkling in layered gel beams. (1st November 2017)

• Record Type: Journal Article
• Authors: Nardinocchi, P.; Puntel, E.
• Is Part Of: Proceedings. Volume 473:Number 2207(2017)
• Publication Date: 2017-11-01
• Subjects: swelling gel -- bilayer beam -- finite strains -- wrinkling -- surface instability -- morphing and sensing; Physical sciences -- Periodicals; Engineering -- Periodicals; Mathematics -- Periodicals; 500
• DOI: 10.1098/rspa.2017.0454
• Languages: English
• ISSNs: 1364-5021

Abstract

Abstract : Gels are widely employed in smart mechanical devices and biomedical applications. Swelling-induced bending actuation can be obtained by means of a simple bilayer gel beam. We show that this system can also exhibit wrinkling patterns of potential interest for structural morphing and sensing. We study swelling-induced wrinkling at the extrados of a bilayer gel beam with the softer layer on top. The bent configuration at finite strain is recovered first and, starting from it, a linear perturbation analysis is performed. We delimit the zone corresponding to wrinkling modes in a parameter plane encompassing a mechanical stiffness ratio and a geometric top layer to total height ratio. Interestingly, we observe that surface instability precedes and envelopes wrinkling modes of finite wavelength. Finally, we discuss the effect of changes in stiffness and of the Flory–Huggins parameters χ on the size of the wrinkling domain.