Interface-exfoliated graphene-based conductive screen-printing inks: low-loading, low-cost, and additive-free

Area of Science:

• Materials Science
• Nanotechnology
• Biomedical Engineering

Background:

• Paper-based diagnostics are increasingly important for accessible healthcare.
• Current conductive inks for these devices are often expensive, require high sintering temperatures, or use harsh stabilizers.

Purpose of the Study:

• To develop an effective, inexpensive, and environmentally friendly graphene ink suitable for screen printing on paper.
• To overcome the limitations of existing conductive ink formulations for next-generation diagnostic devices.

Main Methods:

• Utilized an interfacial trapping method for spontaneous graphite exfoliation to graphene.
• Formulated a viscous graphene-stabilized water-in-oil emulsion using pristine graphite, water, and non-toxic alkanes.
• Investigated drying at 90°C and microwave treatment to enhance conductivity.

Main Results:

• Achieved a conductive graphene ink with a sheet resistance of approximately 600 Ω/sq at a thickness under 6 µm.
• The ink formulation requires minimal processing time (40 s of shaking) and low stabilizer concentration (1 wt% graphite).
• The developed ink is suitable for screen printing on paper substrates without requiring high sintering temperatures.

Conclusions:

• The reported graphene ink offers a cost-effective and environmentally benign solution for manufacturing paper-based diagnostic devices.
• This approach simplifies the production of conductive inks, making advanced diagnostics more accessible.
• The ink's properties are promising for various applications in low-cost, disposable electronic devices.