Rice-inspired oriented copper fiber wick with excellent capillary performance for ultra-thin vapor chamber

作者：Wang, Junxiang; Tang, Yong; Huang, Haoyi; Xi, Xiaoqian; Li, Hongming; Yan, Caiman^*; Zhang, Shiwei

来源：APPLIED THERMAL ENGINEERING, 2024, 236: 121573.

DOI：10.1016/j.applthermaleng.2023.121573

• Ultra-thin copper fiber wick
• Ultra-thin vapor chamber
• Biomimetic structure
• Capillary performance
• Wettability

In response to the current trend of thermal management systems for microelectronic products, ultra-thin vapor chambers (UTVCs) have become an emerging hotspot. Currently, there is an urgent challenge to design of highperformance capillary wicks for use in limited spaces for UTVCs. In this study, an ultra-thin copper fiber wick (UTCFW), inspired by rice plants, was proposed and prepared by the limited fiber sintering and hydraulic pressure methods. By simply varying the fiber length in the mould, it was possible to prepare an UTCFW with ordered orientation similar to the developed root system of the rice plant. A chemical treatment was used to develop micro- and nano-scale structure on the surface of the UTCFW, similar to hairs on roots of the rice plant, which makes the UTCFW exhibit superhydrophilic properties. After optimization, the capillary factor M of the most ordered sample with 80 mm fibers (L80) was 1.254 mu m, which was 567 % times that of the poorly ordered with 5 mm fibers (L5). In short, the bioinspired UTCFW had both excellent wettability and capillary performance. This study demonstrated the preparation of a high-performance and cost-effective UTCFW for improving the thermal performance of UTVCs.