Robust Production of Well‐Controlled Microdroplets in a 3D‐Printed Chimney‐Shaped Milli‐Fluidic Device

3D‐printing technology has recently been exploited in droplet microfluidics due to its simplicity and low cost. Unresolved, however, is the design and fabrication of 3D‐printed droplet generators that allow high throughput production of monodisperse droplets with sizes ranging from tens to hundreds of microns in a robust manner. Herein, a newly designed 3D‐printed milli‐fluidic device with a chimney‐shaped void geometry that produces monodisperse droplets controllably with the size covering a broad range is reported. The droplet generator with four parallelized chimneys is devised to simultaneously generate droplets of various size as well as spherical glycine crystals of various size in a single system, demonstrating its potential as a point‐of‐care medicine manufacturing platform. A new 3D‐printed chimney‐shaped milli‐fluidic device with the tapered void geometry is designed to achieve tunable droplet sizes ranging from tens to hundreds of microns via variation of the flow rate ratio and the tapering angle. Numbering‐up and size screening systems are also developed for point‐of‐care medicine manufacturing applications.