On the basis of a volume of fluid(VOF)liquid/liquid interface tracking method,we apply a two-dimensional model to investigate the dynamic behaviors of droplet breakup through a splitting microchannel.The feasibility a...On the basis of a volume of fluid(VOF)liquid/liquid interface tracking method,we apply a two-dimensional model to investigate the dynamic behaviors of droplet breakup through a splitting microchannel.The feasibility and applicability of the theoretical model are experimentally validated.Four flow regimes are observed in the splitting microchannel,that is,breakup with permanent obstruction,breakup with temporary obstruction,breakup with tunnels,and non-breakup.The results indicate that the increase of the capillary number Ca provides considerable upstream pressure to accelerate the droplet deformation,which is favorable for the droplet breakup.The decrease of the droplet size contributes to its shape changing from the plug to the sphere,which results in weakening droplet deformation ability and generating the nonbreakup flow regime.展开更多
Single cell analysis is of great significance to understand the physiological activity of organisms.Microfluidic droplet is an ideal analytical platform for single-cell analysis. We developed a microfluidic droplet sp...Single cell analysis is of great significance to understand the physiological activity of organisms.Microfluidic droplet is an ideal analytical platform for single-cell analysis. We developed a microfluidic droplet splitting system integrated with a flow-focusing structure and multi-step splitting structures to form 8-line droplets and encapsulate single cells in the droplets. Droplet generation frequency reached1021 Hz with the aqueous phase flow rate of 1 m L/min and the oil phase flow rate of 15 mL /min. Relative standard deviation of the droplet size was less than 5% in a single channel, while less than 6% in all the8 channels. The system was used for encapsulating human whole blood cells. A single-cell encapsulation efficiency of 31% was obtained with the blood cell concentration of 2.5 ？ 104cells/mL, and the multicellular droplet percentage was only 1.3%. The multi-step droplet splitting system for single cell encapsulation featured simple structure and high throughput.展开更多
文摘On the basis of a volume of fluid(VOF)liquid/liquid interface tracking method,we apply a two-dimensional model to investigate the dynamic behaviors of droplet breakup through a splitting microchannel.The feasibility and applicability of the theoretical model are experimentally validated.Four flow regimes are observed in the splitting microchannel,that is,breakup with permanent obstruction,breakup with temporary obstruction,breakup with tunnels,and non-breakup.The results indicate that the increase of the capillary number Ca provides considerable upstream pressure to accelerate the droplet deformation,which is favorable for the droplet breakup.The decrease of the droplet size contributes to its shape changing from the plug to the sphere,which results in weakening droplet deformation ability and generating the nonbreakup flow regime.
基金supported by National Natural Science Foundation of China(Nos.21305010,21375012)Fundamental Research Funds for the Central Universities(No.N140504002)General Scientific Research Projects of Liaoning Provincial Department of Education(No.L2013106)
文摘Single cell analysis is of great significance to understand the physiological activity of organisms.Microfluidic droplet is an ideal analytical platform for single-cell analysis. We developed a microfluidic droplet splitting system integrated with a flow-focusing structure and multi-step splitting structures to form 8-line droplets and encapsulate single cells in the droplets. Droplet generation frequency reached1021 Hz with the aqueous phase flow rate of 1 m L/min and the oil phase flow rate of 15 mL /min. Relative standard deviation of the droplet size was less than 5% in a single channel, while less than 6% in all the8 channels. The system was used for encapsulating human whole blood cells. A single-cell encapsulation efficiency of 31% was obtained with the blood cell concentration of 2.5 ？ 104cells/mL, and the multicellular droplet percentage was only 1.3%. The multi-step droplet splitting system for single cell encapsulation featured simple structure and high throughput.
