3D Printed Leaf-Vein-Like\nAl<sub>2</sub>O<sub>3</sub>/EP Biohybrid Structures with Enhanced\nThermal Conductivity

The high computility of electronic components put urgent\nrequirements\non the dissipation efficiency of a high thermal conductive substrate.\nHerein, inspired by the nature structure, leaf-vein-like Al<sub>2</sub>O<sub>3</sub> skeleton was first designed though topology optimization\nalgorithm and manufactured via vat photopolymerization (VPP) 3D printing,\nthen compounded with epoxy (EP) to prepare leaf-vein-like biohybrid\nstructures. The biohybrid structure had a high λ (14.65 Wm<sup>–1</sup> K<sup>–1</sup> with the solid fraction of\n40 vol %), which was 5585% higher than neat EP and 269% higher than\nthe random dispersed Al<sub>2</sub>O<sub>3</sub>/EP composite at the\nsame solid amount. Moreover, it further showed a high enhancement\nin the cooling ecoefficiency of the lighting-emitting diode (LED)\ncooling system. Compared with 40 vol % random dispersed Al<sub>2</sub>O<sub>3</sub>/EP composite as a cooling substrate, the leaf-vein-like\nbiohybrid structure with the same solid fraction reduced the working\ntemperature of LED by 8.9 °C. Our strategy has a significant\npotential as a viable type and mass-producible bionic cooling substrate.