Low-Temperature Deposition Manufacturing: A Versatile Material Extrusion-Based 3D Printing Technology for Fabricating Hierarchically Porous Materials

Low-temperature deposition manufacturing (LTDM) is a technology that combines material extrusion-based 3D printing and thermally induced phase separation (TIPS) into one process. With this feature, both the merits of 3D printing and TIPS can be incorporated including complex geometries with tailorable ordered macroporous features facilitated by 3D printing and microporous/nanoporous features endowed by TIPS. These macroporous/microporous/nanoporous combined structures are important to some important applications such as tissue engineering scaffolds, porous electrodes for electrochemical energy storage, purification, and filtering applications. However, the unique advantages and potential applications of LTDM have not been fully recognized and exploited yet. In this review, we will discuss the origin, principle, advantages, processes, and machine setup of LTDM technology with an emphasis on its unique advantages in fabricating porous materials. Then, current applications of LTDM including porous tissue engineering scaffolds and emerging porous electrodes for electrochemical storage will be described. The versatility of LTDM including its capability of processing a wide range of materials, multimaterial and gradient structures, and core-shell structures will be introduced. Finally, we will conclude with a perspective and outlook on the future development and applications of LTDM technology.