Cellular-Engineered Titanium heat pipe

Abstract

With the rapid development of electronic devices and electric vehicles, the power density and heat flux of these systems are increasing at unprecedented levels, thereby necessitating effective cooling solutions. Heat pipes offer promising potential owing to their ultrahigh cooling capacity. Hierarchical wicks that ensure both nucleation and strong capillaries against gravity are essential for developing next-generation heat pipes; however, this remains challenging owing to the limited design and manufacturing options. Hence, we present a Ti-based flat heat pipe with three-tier micro/nanostructured cellular wicks fabricated via one-step laser ablation. The multitier structures comprising a cellular base, microchannels, and porous cavities/protrusions provide dense nucleation sites for effective phase change while simultaneously enhancing the capillary for sustainable liquid replenishment at high heat flux. Owing to the excellent coordination between the nucleation and liquid capillary of this hierarchical structure, an assembled Ti heat pipe that weighs only 14.57 g achieves a maximum equivalent thermal conductivity of 35683 W/mK, thus significantly outperforming conventional designs. Even under anti-gravity conditions, it maintains a thermal conductivity 77 folds higher than that afforded by pure Ti. The lightweight design coupled with excellent thermal performance unlocks the full potential of this heat pipe for cooling electronics and aerospace applications, where orientation changes and acceleration actions occur frequently.