Soft Skin Layers Enable Area-Specific, Multiscale Graphene Wrinkles with Switchable Orientations

Area of Science:

• Materials Science
• Nanotechnology
• Mechanical Engineering

Background:

• Graphene's unique properties make it promising for flexible electronics.
• Achieving controlled wrinkling in graphene without cracks is a significant challenge.
• Existing methods often lead to material failure under strain.

Purpose of the Study:

• To report a method for fabricating crack-free graphene wrinkles.
• To demonstrate control over wrinkle spatial wavelengths and orientations.
• To investigate the role of a fluoropolymer layer in wrinkle formation and stability.

Main Methods:

• Supporting graphene on a thin fluoropolymer and prestrained elastomer substrate.
• Inducing conformal wrinkling through strain relief.
• Utilizing mechanical modeling to understand structural evolution.
• Patterning fluoropolymer layers to control wrinkle characteristics.

Main Results:

• Achieved crack-free graphene wrinkles with tunable wavelengths and orientations.
• Demonstrated switchable wrinkle orientations over hundreds of stretching/releasing cycles.
• Confirmed that the fluoropolymer layer prevents crack formation and delamination.
• Showed that patterned fluoropolymer layers enable precise control over wrinkle morphology.

Conclusions:

• The developed method enables robust and controllable graphene wrinkling.
• The fluoropolymer interlayer is crucial for maintaining graphene's mechanical integrity.
• This technique opens possibilities for advanced flexible and stretchable graphene-based devices.