Conductive Inks Based on Melamine Intercalated Graphene Nanosheets for Inkjet Printed Flexible Electronics

Area of Science:

• Materials Science
• Nanotechnology
• Green Chemistry

Background:

• Growing demand for flexible electronics necessitates sustainable mass-production methods.
• Current graphene production often involves harsh chemicals or energy-intensive processes.

Purpose of the Study:

• To develop a scalable, environmentally benign method for producing graphene nanosheets.
• To formulate and inkjet-print a conductive ink using these graphene nanosheets.
• To optimize post-printing processes for reduced electrical resistance in flexible electronics.

Main Methods:

• Mechanochemical exfoliation of graphite with melamine using a planetary ball mill to yield melamine-intercalated graphene nanosheets (M-GNS).
• Formulation of an inkjet-printable conductive ink using M-GNS and green solvents (water, ethanol, ethylene glycol).
• Inkjet printing of conductive patterns on plastic substrates, followed by thermal annealing and intense pulsed light (IPL) treatment.

Main Results:

• Produced M-GNS with small particle sizes (down to 14 nm diameter, 0.4 nm thickness).
• Developed a stable, inkjet-printable conductive ink suitable for plastic substrates.
• Achieved low sheet resistance (5 kΩ/sq for 10 layers, 626 Ω/sq for 20 layers) on polyimide after optimized post-processing.
• Demonstrated a functional flexible printed circuit (LED).

Conclusions:

• The mechanochemical route offers a scalable and eco-friendly approach for graphene production.
• The developed graphene ink and printing process are viable for creating flexible electronics.
• This method provides a sustainable alternative for mass-producing graphene-based printed flexible electronics.