Membrane-based liquid cooling strategy enabling sustainable high-heat-flux thermal management

Liquid cooling is widely recognized for its high thermal efficiency and compact structure in thermal management applications, but it faces challenges in dissipating heat effectively at low flow velocities. This study proposes a novel membrane-based mini-channel heat sink (MMHS) using a hygroscopic fluid, which enhances cooling performance through combined convective and evaporation heat transfer while offering water-saving benefits via self-replenishing moisture absorption. To further improve heat and mass transfer, an inclined grooved structure (EMMHS) was designed to induce transverse swirling and promote internal mixing. Through experimentally validated CFD models, numerical simulations were conducted to investigate the effects of inlet velocity (0.1−0.9 m/s) and channel length (30−50 mm) on thermal and hydraulic performance. Results indicate that MMHS achieves expected evaporation cooling power, contributing 19.3 % of total heat flux at 0.1 m/s, and this value is 26.8 % for EMMHS. For a channel length of 50 mm, EMMHS increases the Nusselt number by 183.0 %, with evaporation cooling power contributing 45.9 % of the total heat flux, enabling a performance evaluation criterion of 2.5. The membrane-based thermal management strategy can keep future 1 nm chips below ∼353 K under a high heat flux of 200 W/cm2, requiring only ultra-low pumping power of 2.3 mW. This work demonstrates the potential of MMHS and EMMHS in addressing thermal management challenges, providing a promising solution for efficient cooling in high-heat-flux applications.