Designing MXene hydrogels for flexible and high-efficiency electromagnetic wave absorption using digital light processing 3D printing

With the rapid advancement of wearable electronic devices in both civilian and military applications, electromagnetic (EM) pollution has become a growing concern, leading to an increased demand for efficient electromagnetic wave (EMW) absorbing materials. Conventional absorbing materials often suffer from limited design flexibility and challenging processing requirements. To address these issues, this study introduces a series of MXene/Polyacrylamide hydrogels (MPH) with excellent EMW absorption properties, fabricated into complex geometric structures using digital light processing (DLP) printing technology. These functional hydrogels feature a three-dimensional (3D) porous architecture, providing robust mechanical properties and exceptional EMW absorption performance. The MXene component, enriched with surface functional groups, not only improves impedance matching but also synergistically interacts with other dissipation mechanisms to enhance overall EMW absorption. Notably, the MPH-1 specimen demonstrates an outstanding effective absorption bandwidth (EAB) of 7.36 GHz at a thickness of 1.95 mm (10.64–18 GHz), and a minimum reflection loss (RL min ) of −38.20 dB at 10.88 GHz at a thickness of 2.40 mm. This work presents a novel and efficient strategy for the rapid and precise fabrication of gel-based functional materials, offering a straightforward method for developing wearable, flexible EMW-absorbing devices with superior properties.