Size-Controlled Preparation of Monodisperse Microbubbles using Co-Flow Glass Capillary Microfluidic Device

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

“…e tapered end of another glass capillary was cut using a microforge (MF-900, Narishige) to obtain an inner diameter (d c ) of 30 µm and this capillary was used as the collection capillary. In general, a device using a collection capillary with a smaller inner diameter can generate smaller monodisperse microbubbles at a higher rate (Kitazaki et al, 2019). However, when the diameter of the collection capillary reached a certain lower limit (i.e., d c =13 µm), smaller microbubbles and a higher generation rate were not obtained because the liquid phase ow rate could not be increased further owing to excessive pressure loss in the narrower collection capillary.…”

“…Furthermore, Zhang et al (2014) presented a simple and inexpensive micro uidic device consisting of two glass capillaries with inner diameters of 2 µm and 75 µm that could generate monodisperse microbubbles with diameters of 3.5-60 µm by changing the liquid phase ow rate and liquid viscosity; however, the generation rate was low (on the order of 10 4 bubbles/s). We previously reported that monodisperse microbubbles with diameters of 4-62 µm and a CV of less than 2% could be generated at rates ranging from 1.6×10 2 to 1.5×10 5 bubbles/s in co-ow type glass capillary micro uidic devices using di erent dimensions of capillaries without requiring the addition of a thickener such as glycerin to the liquid phase (Kitazaki et al, 2019).…”