Efficient thermal management of electronic devices by constructing interlayer phonon bridges.

Area of Science:

• Materials Science
• Nanotechnology
• Thermal Management

Background:

• Layered films are crucial for thermal management, but suffer from limited through-plane heat transfer.
• High in-plane thermal conductivity helps diffuse heat, yet low through-plane conductivity hinders overall device cooling.
• Overcoming this limitation is key for advanced thermal management solutions in electronics.

Purpose of the Study:

• To develop a novel strategy for enhancing both in-plane and through-plane thermal conductivity in layered films.
• To investigate the impact of a honeycomb-gel densification method on thermal transport properties.
• To achieve efficient subambient cooling for heat-generating devices using engineered films.

Main Methods:

• Fabrication of aramid nanofiber/boron nitride nanosheet films.
• Application of a honeycomb-gel densification strategy to create interlayer phonon bridges.
• Characterization of in-plane and through-plane thermal conductivity.
• Evaluation of solar reflectivity, infrared emissivity, and radiative cooling performance.

Main Results:

• The honeycomb-gel densification strategy created continuous, zigzag interlayer phonon bridges.
• In-plane thermal conductivity increased by 488.9% and through-plane conductivity by 503.3% compared to random-gel densified films.
• The engineered films demonstrated efficient subambient cooling of 17.2°C at 100 mW/cm² due to high solar reflectivity and thermal radiation.

Conclusions:

• The honeycomb-gel densification strategy effectively enhances bi-directional thermal pathways in layered films.
• This approach significantly boosts thermal conductivity, addressing a key limitation in current thermal management materials.
• The developed films offer a promising solution for efficient radiative cooling of heat-generating electronic devices.