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Updated: Jun 25, 2026
Generation of Size-controlled Poly (ethylene Glycol) Diacrylate Droplets via Semi-3-Dimensional Flow Focusing Microfluidic Devices
Published on: July 3, 2018
Independent control of drop size and velocity in microfluidic flow-focusing generators using variable temperature and
Claudiu A Stan1, Sindy K Y Tang, George M Whitesides
1Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 01238, USA.
Abstract:
This paper describes a method to control the volume and the velocity of drops generated in a flow-focusing device dynamically and independently. This method involves simultaneous tuning of the temperature of the nozzle of the device and of the flow rate of the continuous phase; the method requires a continuous phase liquid that has a viscosity that varies steeply with temperature. Increasing the temperature of the flow-focusing nozzle from 0 to 80 degrees C increased the volume of the drops by almost 2 orders of magnitude. Tuning both the temperature and the flow rate controlled the drop volume and the drop velocity independently; this feature is not possible in a basic flow-focusing device. This paper also demonstrates a procedure for identifying the range of possible drop volumes and drop velocities for a given flow-focusing device and shows how to generate drops with a specified volume and velocity within this range. This method is easy to implement in on-chip applications where thermal management is already incorporated in the system, such as DNA amplification using the polymerase chain reaction and nanoparticle synthesis.
