Multifunctional Polymer-Metal Lattice Composites via Hybrid Additive Manufacturing Technology

Abstract

With increasing interest in the rapid development of lattice structures, hybrid additive manufacturing (HAM) technology has become a competent alternative to traditional solutions such as water jet cutting and investment casting. Herein, a HAM technology that combines vat photopolymerization (VPP) and electroless/electroplating processes is developed for the fabrication of multifunctional polymer-metal lattice composites. A VPP 3D printing process is used to deliver complex lattice frameworks, and afterward, electroless plating is employed to deposit a thin layer of nickel-phosphorus (Ni-P) conductive seed layer. With the subsequent electroplating process, the thickness of the copper layer can reach 40 μm within 1 h and the resistivity is around 1.9×10−8 Ω⋅m, which is quite close to pure copper (1.7 ×10−8 Ω⋅m). The thick metal shell can largely enhance the mechanical performance of lattice structures, including structural strength, ductility, and stiffness, and meanwhile provide current supply capability for electrical applications. With this technology, the frame arms of unmanned aerial vehicles (UAV) are developed to demonstrate the application potential of this HAM technology for fabricating multifunctional polymer-metal lattice composites.

Mechanical Characterization of Multifunctional Metal-Coated Polymer Lattice Structures

“…Due to their exceptional lightweight performance, discontinuous fracture mechanism, and the metal-based aging retardation of the photopolymer matrix, we have successfully implemented metal-coated BCC lattice structures in a representative application-specifically, the frame arms of unmanned aerial vehicles (UAVs), as illustrated in Figure 1 [42]. In this context, we conduct mechanical characterizations of multifunctional BCC copper-coated lattice structures using a multiscale analysis method.…”