A Review of Research on the Preparation of Janus Particles Based on Microfluidics

Janus particles are a unique class of micro-and nanostructures featuring dual-faced asymmetry, typically composed of chemically, physically, or functionally distinct regions. This anisotropy grants them stable interfacial orientation and imparts exceptional amphiphilicity, surface activity, and self-assembly behavior. However, precisely controlling their morphology and composition remains a major synthetic challenge. In this context, microfluidic technology has emerged as a powerful platform due to its ability to finely manipulate fluid dynamics and interfacial phenomena at the microscale. Widely applied in nanomaterials and drug delivery, microfluidics also offers significant advantages for the tailored synthesis of Janus particles. This review outlines the evolution of microfluidic techniques and highlights their unique strengths in fabricating Janus structures. Based on different mechanisms, microfluidic strategies are classified into two main categories: Droplet-Templated and Flash Nanoprecipitation. Recent advances in each method are discussed with emphasis on their fabrication features. In addition, the review explores the practical relevance of these methods in diverse fields, including Optical Display Technologies, Self-Propelled and Actively Controlled Microparticle Systems, and Biomedical Systems. This work aims to provide insights and references for the future development and functional deployment of Janus particles.