Ultra-thin vapor chambers (UTVCs) are widely used to cool high-power electronics due to their excellent thermal conductivity. In this study, a UTVC of 82 mm × 58 mm × 0.39 mm with composite wick was prepared. The composite wick is composed of two layers of copper mesh and multiple spiral-woven meshes (SWMs), and the composite wick was applied in UTVC to improve liquid replenishment performance and temperature uniformity. Furthermore, the thermal performance of UTVCs with different support column diameters, filling ratios (FRs), and SWM structures was experimentally studied. The results found that the equivalent thermal conductivity (ETC) decreases as the diameter of the support column increases; the UTVC with 0.5 mm support column diameter has the highest ETC, at 3473 W/(m·K). Then, the effect of FR on the heat transfer performance of UTVCs with SWM numbers of 0, 1, 2, and 3 (0 SWMs, 1 SWM, 2 SWMs, 3 SWMs) is consistent, the 30% FR UTVC with 3 SWMs having the highest ETC, at 3837 W/(m·K). Finally, the increased number of SWMs can significantly improve the ultimate power of the UTVCs, the UTVC with 3 SWMs having the highest ultimate power, at 26 W. The above experimental studies indicate that the designed and manufactured UTVCs have great potential advantages in thermal dissipation for electronics.

With the rapid development of electronics, thermal management has become one of the most crucial issues. Intense research has focused on surface modifications used to enhance heat transfer. In this study, multilayer copper micromeshes (MCMs) are developed for commercial compact electronic cooling. Boiling heat transfer performance, including critical heat flux (CHF), heat transfer coefficients (HTCs), and the onset of nucleate boiling (ONB), are investigated. The effect of micromesh layers on the boiling performance is studied, and the bubbling characteristics are analyzed. In the study, MCM-5 shows the highest critical heat flux (CHF) of 207.5 W/cm² and an HTC of 16.5 W(cm²·K) because of its abundant micropores serving as nucleate sites, and outstanding capillary wicking capability. In addition, MCMs are compared with other surface structures in the literature and perform with high competitiveness and potential in commercial applications for high-power cooling.

Ultrathin vapor chamber (UTVC) is considered an ideal solution to the heat dissipation problem of aircraft and spacecraft. However, the cooling performance rapidly deteriorates due to the obstruction of the liquid return flow under acceleration overload, posing a serious threat to the safety of the spacecraft. More seriously, few theoretical models can reveal the mechanism of heat transfer under centrifugal conditions, resulting in an increase in the design cost and difficulty of the anti-centrifugal ultrathin vapor chamber (ACUTVC). Herein, two novel ACUTVCs based on the anti-centrifugal wicks were proposed, which were extensively tested and compared with the UTVC based on the traditional wick. Results show that the effective thermal conductivities of the ACUTVCs exceed 1500 W m−1 K−1 even under extreme conditions of a 6 g acceleration, which are about four times that of copper and comparable to commercial graphene films, demonstrating reliable thermal management capability under high-g conditions. The heat transfer mechanisms under different centrifugal conditions were revealed by the theoretical model proposed in this work, with a maximum error of 26.27% compared to the experimental results, showing a good agreement. Model results highlight the potential optimization approaches of wick structures, which may guide the new directions for the design of the ACUTVC.

Aluminum vapor chambers have become an important component used to solve heat dissipation problems in lightweight applications due to their low density and good heat transfer characteristics. In this paper, a new sintered aluminum powder wick is provided for an aluminum vapor chamber. An aluminum porous wick was sintered using liquid phase sintering technology. Using acetone as the working medium, the influence of the structural parameters of the aluminum wick on its boiling heat transfer performance was studied. The influence of thickness on the boiling heat transfer performance of a sintered porous wick is particularly significant. Thinner, porous wicks have better critical heat flux (CHF). The porosity and particle diameter mainly affect the heat transfer coefficient (HTC). At a low heat flux, the sintered wick with low porosity and a small particle diameter has a higher HTC. The HTC of porous wicks, with a larger particle diameter and porosity, decreases slower. The optimal porosity ranges from 46.4 ± 2.5% to 51.8 ± 2.5%. Compared with the polished aluminum plate, the CHF is increased by 1.7 times, and the HTC is increased by about 4.6 times under the same heat flux.

The aluminum heat pipes have the advantages of lightweight and low-cost, which are widely applied to space satellites. The wick is the critical component of the heat pipe which provides the capillary pressure. Unfortunately, the performance of the aluminum heat pipes is limited by the wicks, which are difficult to manufacture due to the barriers of Al2O3 thin film during the aluminum powder wicks' sintering process. To overcome this problem, a novel sintered aluminum powder wick manufactured by the liquid phase enhance sintering (LPES) technology based on element doping and vacuum sintering was proposed in this work. Considering the material compatibility between the aluminum and working fluid, the brazing powder rich in Si was chosen to be doped to promote the formation of sintered necks. The mechanism of the LPES promoted by the Si was analyzed by thermodynamic and element distribution analysis. The wick is lightweight whose density is only 22.60% and 74.26% of the densities of copper and aluminum. The wettability and capillary performance of the wicks were also studied. The results show that all the samples are superhydrophilic with the working fluids of ethanol and acetone. The sample of CS15 (coarse pure aluminum powder with 15 wt. % brazing powder) has the best wettability and capillary performance in acetone, whose infiltration time, capillary rise height, and wicking coefficient are about 69.50 ms, 106.39 mm, and 12.35 mm/s0.5, respectively. The work provides a feasible approach to manufacturing lightweight and low-cost sintered powder wicks for aluminum heat pipes.