Active Droplet Sorting in Microfluidics

The ability to manipulate and sort droplets is a fundamental issue in droplet-based microfluidics. In this review, we present state-of-the-art technologies which are implemented to efficiently sort droplets. We classify the concepts according to the type of energy implemented into the system. We also discuss various key issues and provide insights into various systems.



  1. Xi, H.-D.; Zheng, H.; Guo, W.; Ganan-Calvo, A. M.; Ai, Y.; Tsao, C.-W.; Zhou, J.; Li, W.; Huang, Y.; Nguyen, N.-T.; Tan, S. H., Active droplet sorting in microfluidics: a review. Lab on a Chip 2017, 17 (5), 751-771.

Droplet and Bubble Coalescence

Bubble coalescence in different salt solutions governs many interesting but unexpected phenomena. These phenomena are found in nature and many industrial applications. We seek to understand the complex physical interaction between such systems.



  1. Wang, J.; Tan, S. H.; Nguyen, A. V.; Evans, G. M.; Nguyen, N.-T., A Microfluidic Method for Investigating Ion-Specific Bubble Coalescence in Salt Solutions. Langmuir 2016, 32 (44), 11520-11524.


Micro lenses with tuneable focal length can find a wide range of applications in lab-on-a-chip (LOC) systems. The integration of micro lenses into microfluidic system can improve the portability and make the system cost-efficient.



  1. Song, C.; Nguyen, N.-T.; Tan, S.-H.; Asundi, A. K., Modelling and optimization of micro optofluidic lenses. Lab on a Chip 2009, 9 (9), 1178-1184.

Automated Droplet Measurement

The ability to rapidly measure different droplet parameters can be an invaluable tool. We developed ADM which is an open source program. The program is freely available at http://a-d-m.weebly.com/.



  1. Speed: 
    More than 15 times faster than the MATLAB based DMV* program.
    Processes about 3000 frames in 10 seconds (520×64 pixels, Lagarith lossless video codec)

    Batch processing:
    Automated processing from a list of avi video files.

    Droplet parameters:
    24 parameters including advancing/receding angle and droplet deformation
  2. Advanced option:
    User defined image processing parameters

    Contour history view:
    Review tracked objects and spotting unusual tracking phenomena.


  1. Chong, Z. Z.; Tor, S. B.; Gañán-Calvo, A. M.; Chong, Z. J.; Loh, N. H.; Nguyen, N.-T.; Tan, S. H., Automated droplet measurement (ADM): an enhanced video processing software for rapid droplet measurements. Microfluidics and Nanofluidics 2016, 20 (4), 1-14.