Bionic design and analysis of 3D-printed lattice structure wicks for heat pipe application

Recently, the metal 3D-printed lattice has been used as the heat pipe wick, which can be flexibly applied to complex heat dissipation conditions. The wick with both great capillarity and permeability shows better hydraulic performance, which is difficult for the existing wicks to ensure simultaneously. Herein, inspired by the plant transport structure, this study designed and investigated the biomimetic lattice (face centered hexagon cubic, FCHC) with both excellent capillary and permeability properties. Through theoretical derivation, numerical analysis, and experimental research, the permeability, capillary transport capacity, and capillary performance parameter ($K/r_{eff}$) of six configurations of lattice structures (SC, BCC, FCC, BCCZ, FCCZ, FCHC) were analyzed. These lattice structures are 1 × 8 × 20 arrays of unit cells (1.5mm × 1.5mm × 1.5 mm), and each type is configured with four different porosity levels (40 %, 50 %, 60 %, 70 %). The biomimetic lattice exhibits the best capillary performance obtained using theoretical analysis or mass-based capillary rise experiment, with the average $K/r_{eff}$ parameters being 134.7 % and 139.8 % higher than that of the current commonly used SC lattice, which verifies the excellence of biomimetic lattice structures. This study provides ideas and methodologies for the optimized design of the 3D-printed metal lattice wick for heat pipe applications, and offers a reference for the rapid and low-cost analysis of their hydraulic performance.