Morphological Diagram of Dynamic-Interfacial-Release-Induced Surface Instability

Abstract

In this study, a morphological diagram was constructed for quantitatively predicting various modes of surface instabilities caused by the dynamic interfacial release of strain in initially flat bilayer composites comprising an elastomer and a capping layer. Theory, experiment, and simulation were combined to produce the diagram, which enables systematic generation of the following instability patterns: wrinkle, fold, period-double, delamination, and coexisting patterns. The pattern that forms is most strongly affected by three experimental parameters: the elastic modulus of the elastomer, the elastic modulus of the capping layer, and the thickness of the capping layer. The morphological diagram offers understanding of the formation of complex patterns and development of their applications. Critically, the wrinkle alignment can be well controlled by changing the direction of the interfacial release to enable the creation of centimeter-sized and highly ordered lamellar wrinkled patterns with a single orientation on a soft elastomer without the need for costly high-vacuum instruments or complex fabrication processes. The method and diagram have great potential for broad use in many practical applications ranging from flexible electronic devices to smart windows.

Fabrication of Stable Liquid-like Wetting Buckled Surfaces as Bioinspired Antibiofouling Coatings by Using Silicon-Containing Block Copolymers

“…Dynamic-interfacial-release-induced surface instability created buckled surfaces of the PS- b -PDMS/PDMS bilayer composites owing to the generation of external stress caused by cross-linking-induced volumetric shrinkage of PDMS. According to our previous study, the geometric parameters of diBCP bilayer wrinkles, including their wavelength and amplitude, are affected by the thickness of the capping layer and the mechanical strength of the bilayer’s components (i.e., the elastic moduli of the diBCP thin film and PDMS substrate in this study). That is, the elastic moduli of the three diBCPs would affect the morphologies of generated buckles because of the different PDMS volume fractions of each sample.…”

“…This method relied upon the kinetic release of local strain, enabled by the greater dissolution of the sacrificial layer along the edges of the multilayer composite. Thermally induced cross-linking caused volumetric shrinkage of the composite, driving the development and stabilization of surface wrinkles. ,, Eventually, buckled PS/PDMS composites and buckled PS- b -PDMS/PDMS composites with PDMS wetting layers were generated and employed in antibiofouling performance tests. In addition, PDMS was grafted onto a glass substrate by immersing clean UV–ozone-irradiated glass in PDMS–Cl solution for 1 h, and then the surface was rinsed with n -hexane to remove the polymer brush that had not grafted to the substrate.…”

Springtail-Inspired Hierarchically Structured Polymer Films as Omniphobic Coatings for Directional Transportation of Liquids

“…In recent years, it has been evidenced that symmetric microwrinkles with precisely controllable orientations and dimensions can be achieved using a versatile interfacial release-controlled approach. − The wrinkle formation relies upon the kinetic release of local strain generated from the elastic modulus mismatch between different layers of a multilayer composite. , The wrinkle arrays can subsequently serve as templates to bring about globally aligned surface wrinkle arrays. Here, a roll-to-roll compatible modified Langmuir–Blodgett methodology is developed to further assemble silica colloidal monolayers onto polymeric wrinkle arrays.…”

Interfacial Wrinkling Structures Based on a Double Cross-Linking Strategy Enable a Dual-Mode Optical Information Encryption

“…14,15 However, optical encryption that utilizes oriented wrinkles depends predominantly on mechanical stimuli, a limitation that results in the loss of encrypted information upon stress relaxation. 16,17 Additionally, the predictability of periodic structures carries a risk of being easily replicated. 18 Therefore, the development of a wrinkling structure with operability, stability, and security is an urgent issue to be addressed.…”

“…Among these, the wrinkling structure exhibits unique advantages because it can be modulated by thermal, magnetic, optical, and mechanical stimuli, , demonstrating distinctive controllability and optical manipulability. Typically, ordered wrinkling structures have been widely used to construct encrypted patterns because the highly periodic distribution allows for precise modulation of optical properties during the fabrication process. , However, optical encryption that utilizes oriented wrinkles depends predominantly on mechanical stimuli, a limitation that results in the loss of encrypted information upon stress relaxation. , Additionally, the predictability of periodic structures carries a risk of being easily replicated . Therefore, the development of a wrinkling structure with operability, stability, and security is an urgent issue to be addressed.…”