Parametrically Engineered Laser-Induced Graphene with Tunable Electrical and Morphological Properties for Flexible...

Area of Science:

• Materials Science
• Nanotechnology
• Flexible Electronics

Background:

• Laser-induced graphene (LIG) offers a scalable method for creating 3D porous graphene on polymers.
• Reproducible control of LIG's electrical and structural properties is difficult due to complex laser parameters.

Purpose of the Study:

• To systematically investigate how laser power, scan speed, DPI, EPUA, and DOF affect LIG properties.
• To optimize LIG fabrication for high-quality, conductive graphene on polyimide substrates.
• To demonstrate LIG's potential in flexible electronic devices.

Main Methods:

• Fabrication of LIG on polyimide using a laser system.
• Systematic variation of laser processing parameters (power, scan speed, DPI, EPUA, DOF).
• Characterization of LIG morphology, crystallinity (ID/IG ratio, La), and conductivity (sheet resistance).
• Fabrication and testing of LIG-based flexible piezoresistive sensors and electrothermal heaters.

Main Results:

• Optimized LIG achieved excellent structural quality (ID/IG ~ 0.25, La ~ 76 nm) and low sheet resistance (~10 Ω/□).
• Flexible pressure sensors showed distinct sensitivity regimes, low detection limit (~150 mN), and minimal hysteresis (~5-6%).
• LIG microheaters reached 201 °C in 6.2 s at 6.5 V, demonstrating high heating efficiency.

Conclusions:

• A framework for engineering high-quality, tunable LIG properties was established.
• LIG shows significant potential for scalable, low-power, multifunctional flexible electronic applications.
• Deformation-induced modulation of conductive pathways governs the piezoresistive behavior in LIG sensors.