Abstract
Over the past few decades, there has been an increasing interest in the fabrication of complex high-resolution three-dimensional (3D) architectures at micro/nanoscale. These architectures can be obtained through conventional microfabrication methods including photolithography, electron-beam lithography, femtosecond laser lithography, nanoimprint lithography, etc. However, the applications of these fabrication methods are limited by their high costs, the generation of various chemical wastes, and their insufficient ability to create high-aspect-ratio 3D structures. High-resolution 3D printing has recently emerged as a promising solution, as it is capable of building multifunctional 3D constructs with optimal properties. Here we present a review on the principles and the recent advances of high-resolution 3D printing techniques, including two-photon polymerization (TPP), projection microstereoLithography (PµSL), direct ink writing (DIW) and electrohydrodynamic printing (EHDP). We also highlight their typical applications in various fields such as metamaterials, energy storage, flexible electronics, microscale tissue engineering scaffolds and organ-on-chips. Finally, we discuss the challenge and perspective of these high-resolution 3D printing techniques in technical and application aspects. We believe that high-resolution 3D printing will eventually revolutionize the microfabrication processes of 3D architectures with high product quality and diversified materials. It will also find applications in a wide scope.