Next Article in Journal
Highly Efficient Flame Retardant Hybrid Composites Based on Calcium Alginate/Nano-Calcium Borate
Previous Article in Journal
Metal(II) Coordination Polymers Derived from Mixed 4-Imidazole Ligands and Carboxylates: Syntheses, Topological Structures, and Properties
Article Menu
Issue 6 (June) cover image

Export Article

Open AccessArticle
Polymers 2018, 10(6), 624;

Surface Instability of Bilayer Hydrogel Subjected to Both Compression and Solvent Absorption

4,* and 4,*
College of Aerospace Engineering, Chongqing University, Chongqing 400017, China
Department of Mechanical Engineering and Institute of Materials Science, University of Connecticut, Storrs, CT 06269, USA
Institute of High Performance Computing, A*STAR, Singapore 138632, Singapore
State Key Laboratory of Structural Analysis for Industrial Equipment, International Research Center for Computational Mechanics, Department of Engineering Mechanics, Dalian University of Technology, Dalian 116024, China
These authors contributed equally to this work.
Authors to whom correspondence should be addressed.
Received: 10 May 2018 / Revised: 1 June 2018 / Accepted: 3 June 2018 / Published: 6 June 2018
Full-Text   |   PDF [2863 KB, uploaded 6 June 2018]   |  


The bilayered structure of hard thin film on soft substrate can lose stability and form specific patterns, such as wrinkles or creases, on the surface, induced by external stimuli. For bilayer hydrogels, the surface morphology caused by the instability is usually controlled by the solvent-induced swelling/shrinking and mechanical force. Here, two important issues on the instability of bilayer hydrogels, which were not considered in the previous studies, are focused on in this study. First, the upper layer of a hydrogel is not necessarily too thin. Thus we investigated how the thickness of the upper layer can affect the surface morphology of bilayer hydrogels under compression through both finite element (FE) simulation and theoretical analysis. Second, a hydrogel can absorb water molecules before the mechanical compression. The effect of the pre-absorption of water before the mechanical compression was studied through FE simulations and theoretical analysis. Our results show that when the thickness of the upper layer is very large, surface wrinkles can exist without transforming into period doublings. The pre-absorption of the water can result in folds or unexpected hierarchical wrinkles, which can be realized in experiments through further efforts. View Full-Text
Keywords: hydrogel; hierarchical wrinkles; surface instability; finite element simulation hydrogel; hierarchical wrinkles; surface instability; finite element simulation

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Zhou, Z.; Li, Y.; Guo, T.F.; Guo, X.; Tang, S. Surface Instability of Bilayer Hydrogel Subjected to Both Compression and Solvent Absorption. Polymers 2018, 10, 624.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Polymers EISSN 2073-4360 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top