Acoustic field coupled with hierarchical microstructures for enhanced phase-change thermal management

Phase-change cooling is critical for frontier technologies such as high-power electronics and aerospace. However, the practical application is often constrained by the critical heat flux (CHF) limit. To address this bottleneck, a synergistic enhancement strategy that combines active acoustic excitation with passive hierarchical microstructures is proposed to achieve a breakthrough in pool boiling performance. Through a hybrid fabrication process combining precision CNC machining and nanosecond laser ablation, a hierarchical laser-ablated micro-pin-finned surface (HPFL) was engineered. The multiscale geometric architecture reconstructs bubble dynamics by regulating the distribution of characteristic bubble sizes, thereby reducing the probability of multiple scattering and effective attenuation during acoustic propagation and ensuring efficient acoustic–bubble coupling. The acoustic radiation force acts synergistically with the surface structures to increase bubble detachment frequency while limiting bubble coalescence and vapor film formation. Furthermore, the macroscopic acoustic streaming couples with capillary forces to establish an efficient liquid transport pathway, effectively delaying the dryout of the surface microlayer. Consequently, the HPFL surface exhibits a nonlinear synergistic gain. Compared with a smooth surface, the CHF and heat transfer coefficient are enhanced by 787% and 348.38%, respectively, representing a performance level that surpasses most existing reports. This work provides a scalable and effective solution for thermal management in demanding environments such as high-performance computing and avionics.