The 3D Printing of Flexible Materials: Technologies, Materials, and Challenges

Due to their unique functional properties, such as deformability, bendability, stretchability, and even biocompatibility, sensing, or actuation, flexible materials have become an indispensable and crucial component in electronic systems such as wearable electronic devices and soft robots. Facing the complex demands of various application scenarios, 3D printing technology can be utilized to customize the preparation of various flexible materials into desired shapes. However, compared to rigid materials, flexible materials still face printing issues such as pore defects and weak interlayer bonding during the 3D printing process. Therefore, this paper focuses on analyzing the key bottleneck issues and technical challenges currently existing in flexible material 3D printing technology, and provides an overview of the progress in preparing flexible materials using 3D printing technologies, such as Material Extrusion and Vat Polymerization. Finally, it looks forward to the technical challenges and future development of 3D printing with flexible materials.