Strain Sensing Based on Multiscale Composite Materials Reinforced with Graphene Nanoplatelets

Area of Science:

• Materials Science
• Nanotechnology
• Electrical Engineering

Background:

• Graphene nanoplatelets (GNPs) are promising for conductive composites.
• Functionalization of GNPs can tune material properties.
• Self-sensing composite materials are crucial for structural health monitoring.

Purpose of the Study:

• To investigate the electrical response of NH2-functionalized graphene nanoplatelets (NH2-GNPs) composite materials under strain.
• To develop and compare two manufacturing methods for creating conductive networks using NH2-GNPs.
• To evaluate the potential of these materials as advanced strain sensors.

Main Methods:

• Two fabrication techniques: (a) incorporating NH2-GNPs into epoxy and (b) coating glass fabric with NH2-GNP-filled sizing.
• Measurement of in-plane electrical conductivity and electrical resistance under varying strain levels.
• Comparison of material sensitivity against commercially available strain gauges.

Main Results:

• Both composite types exhibited exponential resistance increase with strain due to nanoparticle distancing and contact loss.
• The materials demonstrated higher sensitivity than commercial strain gauges.
• NH2-GNP coated fabrics showed nearly an order of magnitude greater sensitivity compared to metallic foil strain gauges.

Conclusions:

• NH2-functionalized graphene nanoplatelets composites offer superior piezoresistive sensing performance.
• The developed manufacturing methods enable self-sensing capabilities for structural health monitoring in challenging environments like offshore wind farms.
• The high sensitivity of NH2-GNP coated fabrics positions them as ideal smart fabrics for precise human motion monitoring.