High-Performance Microchannel Flow Boiling Enhanced by Dual-Bionic Micro/Nano-Structures

Area of Science:

• Materials Science
• Heat Transfer
• Fluid Dynamics

Background:

• Microchannel flow boiling is a promising electronic cooling technology.
• Effective control over bubble dynamics, particularly departure, is crucial for performance enhancement.
• Existing methods struggle with efficient bubble management in microscale heat sinks.

Purpose of the Study:

• To develop a dual-bionic micro/nano-structured surface for mediating bubble departure in microchannels.
• To enhance the thermo-hydrodynamic performance of microchannel flow boiling.
• To improve heat dissipation capabilities for high-power electronics.

Main Methods:

• Fabrication of a microchannel heat sink with dual-bionic micro/nano-structures inspired by natural designs (Nepenthes alata peristome and phalarope beak).
• Experimental investigation of flow boiling performance under varying conditions.
• Analysis of bubble dynamics and heat transfer mechanisms.

Main Results:

• The bionic micro/nano-structured surface significantly improved thermo-hydrodynamic performance compared to a smooth surface.
• Achieved a critical heat flux of 366.5 W·cm⁻² and a heat transfer coefficient of 11.8 W·cm⁻²·K⁻¹ at 600 kg·m⁻²·s⁻¹.
• Demonstrated an 82.5% increase in critical heat flux and a 103.2% increase in heat transfer coefficient.

Conclusions:

• The dual-bionic architecture effectively mediates bubble departure through a dual mechanism involving interfacial energy gradients and net forces (buoyancy and drag).
• The developed cooling strategy shows superior performance compared to conventional air/water-based methods for CPU cooling.
• This bionic design offers a promising solution for the demanding cooling requirements of high-power electronics.