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Updated: May 3, 2026

Generation of Size-controlled Poly ethylene Glycol Diacrylate Droplets via Semi-3-Dimensional Flow Focusing Microfluidic Devices
Published on: July 3, 2018
Glass capillary microfluidics for production of monodispersed poly (DL-lactic acid) and polycaprolactone
Goran T Vladisavljević1, Hamed Shahmohamadi2, Diganta B Das1
1Department of Chemical Engineering, Loughborough University, Loughborough LE11 3TU, United Kingdom.
Hypothesis:
Droplet size in microfluidic devices is affected by wettability of the microfluidic channels. Three-dimensional countercurrent flow focusing using assemblies of chemically inert glass capillaries is expected to minimize wetting of the channel walls by the organic solvent.
Experiments:
Monodispersed polycaprolactone and poly(lactic acid) particles with a diameter of 18-150 μm were produced by evaporation of solvent (dichloromethane or 1:2 mixture of chloroform and toluene) from oil-in-water or water-in-oil-in-water emulsions produced in three-dimensional flow focusing glass capillary devices. The drop generation behaviour was simulated numerically using the volume of fluid method.
Findings:
The numerical results showed good agreement with high-speed video recordings. Monodispersed droplets were produced in the dripping regime when the ratio of the continuous phase flow rate to dispersed phase flow rate was 5-20 and the Weber number of the dispersed phase was less than 0.01. The porosity of polycaprolactone particles increased from 8 to 62% when 30 wt% of the water phase was incorporated in the organic phase prior to emulsification. The inner water phase was loaded with 0.156 wt% lidocaine hydrochloride to achieve a sustained drug release. 26% of lidocaine was released after 1 h and more than 93% of the drug was released after 130 h.

