Room temperature rubbing for few-layer two-dimensional thin flakes directly on flexible polymer substrates

Area of Science:

• Materials Science
• Nanotechnology
• Surface Science

Background:

• Few-layer two-dimensional (2-D) thin flakes on flexible polymers are crucial for stretchable electronics.
• Existing fabrication methods often involve indirect transfer steps, limiting scalability and applicability.
• Previous transfer-free methods were restricted to graphene, excluding other 2-D materials.

Purpose of the Study:

• To develop a versatile, transfer-free method for fabricating various few-layer 2-D thin flakes on flexible substrates.
• To enable direct fabrication of materials like hexagonal boron nitride (h-BN), molybdenum disulphide (MoS₂), and tungsten disulphide (WS₂) alongside graphene.
• To achieve strong adhesion of 2-D flakes to polymer substrates at room temperature.

Main Methods:

• A room-temperature rubbing technique utilizing friction was employed.
• Commercial bulk 2-D materials (graphite, h-BN, MoS₂, WS₂) were used as precursors.
• Direct fabrication on flexible polymer substrates was performed without any transfer steps.

Main Results:

• Successfully fabricated few-layer 2-D thin flakes of graphene, h-BN, MoS₂, and WS₂.
• The fabrication process, based on friction, was completed in minutes at room temperature.
• The resulting few-layer 2-D thin flakes exhibited strong adhesion to the flexible polymer substrates.

Conclusions:

• The proposed friction-based room-temperature rubbing method is a viable transfer-free approach for diverse few-layer 2-D thin flakes.
• This technique overcomes limitations of previous methods, enabling broader applications in flexible and stretchable electronics.
• The strong adhesion achieved is advantageous for the long-term stability and performance of 2-D material-based devices.