Yield-Stress Composite Fluids With High Thermal Conductivity and Tunable Rheology via Hierarchical Filler...

Area of Science:

• Materials Science
• Rheology
• Thermal Engineering

Background:

• Yield-stress fluids offer tunable mechanical properties, transitioning between solid and liquid states.
• Conventional yield-stress fluids face a trade-off between viscosity and thermal conductivity, limiting thermal management applications.

Purpose of the Study:

• To develop a yield-stress fluid with enhanced thermal conductivity and controllable rheological properties for thermal management.
• To overcome the limitations of traditional materials in balancing viscosity, yield stress, and thermal performance.

Main Methods:

• Incorporation of multi-sized aluminum nitride particles into a polydimethylsiloxane (PDMS) matrix to create a hierarchical filler architecture.
• Rheological characterization to assess viscosity, yield stress, and thixotropic recovery.
• Physics-informed neural network (PINN) modeling for performance analysis.

Main Results:

• Achieved a yield-stress composite fluid with low viscosity (731.3 Pa·s at 10 s⁻¹), tunable yield stress (37.3–802.3 Pa), and high thermal conductivity (12.0 W·m⁻¹·K⁻¹).
• Demonstrated excellent thixotropic recovery and mechanical robustness.
• The material's dual liquid-like and solid-like states enable efficient distribution and long-term reliability as a thermal interface material.

Conclusions:

• The hierarchical filler architecture strategy successfully creates advanced yield-stress fluids with desirable rheological and thermal properties.
• This approach offers a new pathway for designing high-performance thermal interface materials for demanding applications.
• The developed fluid shows significant potential for improving thermal management systems.