As electronic devices become increasingly powerful and compact, efficient heat dissipation has become a major challenge. Thermal interface materials (TIMs) are placed between heat-generating components and heat sinks to facilitate heat transfer, but traditional TIMs often struggle to combine high thermal conductivity with the softness needed to fill microscopic air gaps.
Now, researchers from the Institute of Metal Research, Chinese Academy of Sciences, and their collaborators have developed a novel TIM that overcomes this trade-off. As reported in the journal Advanced Nanocomposites , the team constructed a vertically oriented porous skeleton using short carbon fibers (CFs)—which have an exceptional axial thermal conductivity of 900 W/m·K—and bridged them with a small amount of graphene oxide (GO).
"Graphene oxide acts as an inorganic adhesive," explains Dr. Han Wang, co-corresponding author of the study. "It effectively bonds individual carbon fibers together through π–π interactions, creating continuous thermal transport pathways while significantly reducing interfacial thermal resistance. This is a key advantage over traditional polymer binders like cellulose, which hinder heat flow."
Using a directional freezing technique followed by vacuum-assisted infiltration of polydimethylsiloxane (PDMS), the team produced composites with a well-aligned porous architecture. “At a carbon fiber loading of just 25.2 wt%, the resulting CF-GO/PDMS composite achieved a through-plane thermal conductivity of 7.61 W/m·K—a 41-fold increase over neat PDMS and a 57.6% improvement over composites made with cellulose binders,” shares Wang.
Notably, the thermal conductivity enhancement efficiency reached 162.9% per 1 wt% filler addition, outperforming most previously reported CF/PDMS composites.
“The porous structure constructed from short-cut fibers allows the material to deform easily under pressure,” says co-corresponding author Professor You Zeng. “The composite exhibited a low compressive modulus of only 6.91 MPa, ensuring it can conform to uneven surfaces and fill air gaps without damaging delicate electronic components.”
Cyclic compression tests further confirmed its excellent mechanical stability and resilience.
"Our findings demonstrate that using graphene oxide as a nanoscale bridge—rather than as a primary filler —can unlock the full potential of high-conductivity carbon fibers” adds Zeng. "We believe this strategy offers a practical and scalable route to next-generation thermal interface materials for advanced electronics cooling.”
The study was supported by the National Natural Science Foundation of China and several provincial science and technology programs. The team plans to further optimize the structure and explore covalent bonding strategies to push thermal conductivity even higher for engineering applications.
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Contact the author :
Prof. You Zeng, Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, PR China
Email: yzeng@imr.ac.cn
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Advanced Nanocomposites
Experimental study
Not applicable
Vertically oriented carbon fiber skeletons bridged with graphene oxide for high thermal conductivity and superior compressibility in polymer-based thermal interface materials
The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Jiangang Zhang is currently employed by Xi'an Rare Metal Materials Institute Co. Ltd. And the other authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.