Embedded 3D Printing of Mechanically Robust Ionogel Composites

Multifunctional materials with programmable mechanical properties and electronic/ionic conductivities are required for many emerging applications, including soft electronics, robotics, structural batteries, and more. Additive manufacturing has revolutionized our ability to fabricate these materials, which often require complex 3D forms. Poly(ionic liquid) composites are an emerging structural electrolyte that provide a wide electrochemical window and high ionic conductivity. However, poor intrinsic mechanical properties (e.g. Young’s modulus) limit the printability of precise functional poly(ionic liquid) architectures, hindering their potential utility as materials for the aforementioned applications. Moreover, existing light-based 3D printing methods are often incompatible with filler particles that can enhance the mechanical properties of poly(ionic liquids) or provide additional functionalities. In this work, we present a method for overcoming the challenges of 3D printing poly(ionic liquids) via embedded 3D (EMB3D) printing. Our integrated material design and manufacturing process produces free-form, lightweight, and flexible poly(ionic liquid) composites that are mechanically robust under cyclic compression. We demonstrate the modularity of our methods by showcasing multimaterial printing with various particle fillers (e.g., carbon black, hexagonal boron nitride, and fumed silica) and poly(ionic liquid)s. We anticipate our contributions will open new avenues for fabricating complex, architected solid electrolytes for soft sensors and robots, wearable devices, solid-state batteries, and more.