Additive Manufacturing of Ti3 C2 MXene-Functionalized Conductive Polymer Hydrogels for Electromagnetic-Interference Shielding.

The ongoing miniaturization of devices and development of wireless and implantable technologies demand electromagnetic interference (EMI) shielding materials with customizability. Additive manufacturing of conductive polymer hydrogels with favourable conductivity and biocompatibility can offer new opportunities for EMI shielding applications. However, simultaneously achieving high conductivity, design freedom, and shape fidelity in 3D printing of conductive polymer hydrogels is still very challenging. Here, an aqueous Ti3 C2 MXene-functionalized PEDOT:PSS ink is developed for extrusion printing to create 3D objects with arbitrary geometries, and a freeze-thawing protocol is proposed to transform the printed objects directly into highly conductive and robust hydrogels with high shape fidelity in both macro and micro scales. The as-obtained hydrogel exhibits a high conductivity of 1525.8 S m-1 at water content up to 96.6 wt% and also satisfactory mechanical properties with flexibility, stretchability, and fatigue resistance. Furthermore, we demonstrate the use of the printed hydrogel for customizable EMI shielding applications. The proposed easy-to-manufacture approach, along with the highlighted superior properties, expands the potential of conductive polymer hydrogels in future customizable applications and represents a real breakthrough from the current state-of-the-art. This article is protected by copyright. All rights reserved.