Curvature induced hierarchical wrinkling patterns in soft bilayers

Area of Science:

• Materials Science
• Mechanical Engineering
• Surface Science

Background:

• Uniaxial compressive strain on film-substrate bilayers causes sinusoidal wrinkling above a critical strain.
• Core-shell soft cylinders exhibit wrinkling pattern evolution from sinusoidal to diamond-like modes under axial compression, influenced by material properties and system curvature.

Purpose of the Study:

• To propose a strategy for fabricating hierarchical wrinkling patterns by controlling the curvature of a film-substrate system.
• To quantitatively understand the evolution of wrinkling patterns using computational modeling.
• To investigate the wetting properties of the fabricated hierarchical surfaces.

Main Methods:

• Fabrication of hierarchical wrinkling patterns by controlling film-substrate curvature.
• Three-dimensional finite element modeling to simulate wrinkling pattern evolution.
• Experimental investigation of surface wetting properties.

Main Results:

• Hierarchical wrinkling patterns were successfully fabricated by controlling curvature.
• A phase diagram was developed based on theoretical analysis and finite element simulations to guide experimental design.
• The hierarchical surface wrinkles resulted in tunable anisotropic wetting behavior, dependent on compressive strain.

Conclusions:

• Controlling curvature is an effective strategy for creating hierarchical wrinkling patterns.
• The developed phase diagram aids in designing experiments for controlled wrinkling.
• The tunable anisotropic wetting surfaces have potential applications in sensors, fluidic devices, micro-reactors, and biomedical devices.