Hoop compression driven instabilities in spontaneously formed multilayer graphene blisters over a polymeric substrate

Area of Science:

• Materials Science
• Mechanical Engineering
• Physics

Background:

• Elastic membrane blistering is susceptible to mechanical instabilities.
• Solid-based instabilities in indented elastic membranes over rigid substrates are well-studied.
• Integrated studies on spontaneous blistering instabilities in 2D materials are lacking.

Purpose of the Study:

• To investigate spontaneous blister formation in multilayer graphene (MLG) flakes on polymeric substrates.
• To elucidate the mechanisms and governing parameters of elastic-solid and viscoelastic-substrate instabilities.
• To propose a blister-collapse model for understanding these instabilities.

Main Methods:

• Extensive experimental analysis of blister formation.
• Analytical investigation of spontaneous blistering.
• Development and application of a blister-collapse model.

Main Results:

• Identified mechanisms for elastic-solid and viscoelastic-substrate instabilities in MLG blisters.
• Proposed a blister-collapse model where confined matter phase transition suppresses hoop compression, driving instabilities.
• Demonstrated that blister-height to flake-thickness ratio, influenced by taper-angle and elasticity, impacts viscous fingering dynamics.

Conclusions:

• The study provides a comprehensive understanding of spontaneous blistering instabilities in 2D materials.
• The proposed blister-collapse model offers insights into the role of confined matter and substrate viscoelasticity.
• Findings are crucial for designing and fabricating advanced 2D material-based devices.