Controlling line defects in wrinkling: a pathway towards hierarchical wrinkling structures

Area of Science:

• Materials Science
• Surface Engineering
• Soft Matter Physics

Background:

• Microscopic wrinkling on elastomeric surfaces is a common phenomenon.
• Controlling wrinkle morphology and defect formation is crucial for applications.
• Existing methods lack precise control over line defect localization.

Purpose of the Study:

• To demonstrate a novel approach for controlling line defect formation in microscopic wrinkling structures.
• To investigate the influence of patterned plasma treatment on wrinkle characteristics.
• To enable programming of hierarchical wrinkling patterns.

Main Methods:

• Patterned plasma treatment of polydimethylsiloxane (PDMS) surfaces under uniaxial stretching.
• Regulation of wrinkling wavelength using treatment time and plasma gases (H2, N2).
• Atomic Force Microscopy (AFM) and finite element methods (FEM) for characterization and analysis.

Main Results:

• Wrinkling wavelength (λ) successfully controlled by plasma treatment parameters.
• Abrupt changes in wavelength created line defects at boundary zones.
• Achieved dramatic wavelength changes up to a factor of 7, controlling branching zones.
• Demonstrated fixed and alternating branching behaviors in wrinkling patterns.

Conclusions:

• Patterned plasma treatment offers precise control over line defect formation in wrinkling structures.
• The findings enable the programming of hierarchical wrinkling patterns.
• Potential applications in optics, tribology, and biomimetic surface structuring are highlighted.