Generation of Monodisperse Microbubbles with a Controlled Size of Less Than 10 µm at a Generation Rate on the Order of 10⁵ Bubbles/s in Glass Capillary Microfluidic Devices

Abstract

Inexpensive glass capillary microfluidic devices with co-flow geometry were prepared to generate highly monodispersed microbubbles with a controlled size of less than 10 µm for medical applications. In the analysis, the dimensions of the injection and collection capillaries were decreased, and the gas pressure and liquid phase flow rate were increased to their respective limits. The diameter of the monodisperse microbubbles (having a coefficient of variation of less than 1.5%) could be controlled within the range of 2.4–9.2 µm, while maintaining a generation rate on the order of 10⁵ bubbles/s by adjusting the inner tip diameter of the injection capillary and the liquid phase flow rate. The inner diameter of the collection capillary was 30 µm, and the gas pressure was 0.50 MPa.