Graphene-Based 3D Printing Composite Materials: Ideal for Heatsinks and Shielding Applications
Introduction
Graphene-structured 3D-printed composites have become ideal choices for applications such as heatsinks and shielding plates. Researchers developed a composite material with vertically aligned particles at specific printing speeds, enhanced for strength and conductivity, making it a strong candidate for military uses, such as 3D-printed heatsinks and shielding plates.
Material Versatility and Optimization
A wide range of matrix and filler combinations make printed materials adaptable for various applications. By adjusting processing methods, scientists can recommend guidelines for maximizing composite material effectiveness and performance. With graphene nanoplatelets (GNP) providing superior thermal and electrical properties, they’re particularly well-suited for these roles. Epoxy resin, known for its flexibility and ease of processing, combines well with GNP to form efficient thermal interface materials. However, the performance of such composites depends on several factors, including the ink’s rheology and GNP concentration, areas that are still being fully explored.
3D Printing GNP-Loaded Composites
Direct Ink Writing (DIW) has been shown to align particles with the printing direction due to shear forces on GNP fillers, but the exact impact on conductivity remains under study. The research team aims to understand this alignment mechanism to optimize lightweight, conductive composites for applications like those of the U.S. Air Force.
Optimized Ink Formulation
To create an optimal graphene structure, the team developed a new ink with GNP concentrations from 7% to 18%. This custom material was loaded into an nScrypt 3Dn-300 system and deposited at different speeds and pressures, achieving a high-volume data set. Post-printing, samples were measured for resistance via X-ray and microscopy techniques. Results showed inks with over 13% GNP displayed enhanced shear-thinning behavior, producing samples with improved strength and conductivity.
Enhanced Conductivity through Speed Variations
Increasing the printing speed from 5 mm/s to 40 mm/s intensified shear forces, aligning GNP particles in the printing direction and achieving conductivity up to 619 S/cm, significantly higher than conventional injection-molded parts.
Significance and Future Applications
The parameters established represent a cost-effective, efficient method for controlling particle alignment in polymer nanocomposites. Backed by the U.S. Air Force Research Laboratory, this material shows potential in military applications such as corrosion-resistant coatings and shielding layers.
Broader Impact and Related Research
Graphene’s intrinsic electrical properties make it well-suited for 3D-printed electronics, and numerous studies have explored its potential in this area. Notably, in November 2020, University of Nottingham scientists advanced additive manufacturing of electronics by creating multilayer graphene structures suitable for enhanced semiconductor applications. Additionally, U.S. researchers have used Aerosol Jet Printing (AJP) to create food detection sensors and a USC team developed novel self-sensing armor using graphene, envisioning future military applications.
The researchers detailed their findings in their paper titled “Printability and Performance of 3D Conductive Graphene Structures.”