Droplet microfluidics for biomedical applications: emerging trends and future developments

Droplet-based microfluidics has witnessed tremendous progress in the past two decades, and this technique has been demonstrated as one of the most promising technologies to synthesize high-end and versatile materials with advanced functions, which provide great possibilities for numerous applications. Herein, the recent progress in preparing high-value natural microspheres by droplet-based microfluidic techniques is summarized comprehensively. We start with an in-depth articulation of the working principles of droplet-based microfluidics and surface modification for microdevices. Subsequently, droplet-based microspheres' fabrication methods have been discussed and summarized. Furthermore, the emerging representative biomedical applications of the different types of natural microspheres are outlined systematically. After that, we consider the challenges that hinder droplet-based microfluidic improvement in academic and industrial applications. Eventually, we will point out the perspectives of droplet-based microfluidics and aim to advance droplet-based microfluidics and sophisticated applications. The scope of this review is not only to offer an in-depth understanding of droplet-based microfluidics but also to open new pathways for versatile applications.