Effect of printing parameters and triply periodic minimal surfaces on electromagnetic shielding efficiency of polyvinylidene fluoride graphene nanocomposites

Abstract

Electromagnetic interference (EMI) shielding is vital in safeguarding electronic devices from the harmful effects of external electromagnetic signals, a critical factor in ensuring the reliability and functionality of these systems. EMI, originating from a myriad of sources, can range from causing temporary disruptions to catastrophic system failures and potentially harmful consequences. This study delves into the EMI shielding capabilities of 3D printed Polyvinylidene Fluoride (PVDF)-graphene Triply Periodic Minimal Surface (TPMS) structures, fabricated using Material Extrusion (ME) process. The focus on TPMS structures stems from their unique geometrical configurations, offering promising potentials in enhancing EMI shielding effectiveness. Four distinct TPMS topologies—gyroid, Neovius, diamond, and I-WP were explored, with each demonstrating varying degrees of shielding effectiveness. 3D printed solid samples showed an average specific shielding effectiveness (SSE) of 13 dB cm³/g, and Neovius triply periodic minimal surface (TPMS) structure exhibited an average SSE of 94 dB cm³/g. Absolute shielding effectiveness (SSE/t) for solid samples and Neovius TPMS structure is around 66 dB cm²/g and 62.5 dB cm²/g respectively. Among the tested samples, those with a Neovius topology emerged as particularly promising, exhibiting high EMI shielding effectiveness suitable for commercial applications. Furthermore, the study investigates the impact of several design and printing parameters, including relative density/infill percentage, print orientation, and the size of unit cells, on total shielding effectiveness (SE_T). Results revealed SE_T variations ranging between 25 dB and 75 dB, suggesting that tuning the SE_T of these samples is feasible by adjusting these parameters. The study's findings, highlighting a strong correlation between SE_T and frequency influenced by unique geometrical characteristics and frequency-dependent interactions, underscore the potential of architected PVDF-graphene TPMS structures in EMI shielding applications. This opens new avenues for research and development in this field, paving the way for more advanced and effective EMI shielding solutions.