On‐Site Formation of Emulsions by Controlled Air Plugs |
| |
| Authors: | Xiaowen Huang Wenli Hui Chonglei Hao Wanqing Yue Mengsu Yang Yali Cui Zuankai Wang |
| |
| Affiliation: | 1. Department of Mechanical and Biomedical Engineering, City University of Hong Kong, , Hong Kong, China;2. Department of Biology and Chemistry, City University of Hong Kong, , Hong Kong, China;3. Key Laboratory of Biochip Technology, Biotech and Health Centre, Shenzhen Research Institute of City University of Hong Kong, , Shenzhen, China;4. The College of Life Sciences, Northwest University, , Xi'an, Shaanxi, China |
| |
| Abstract: | Air plugs are usually undesirable in microfluidic systems because of their detrimental effect on the system's stability and integrity. By controlling the wetting properties as well as the topographical geometry of the microchannel, it is reported herein that air plugs can be generated in pre‐defined locations to function as a unique valve, allowing for the on‐site formation of various emulsions including single‐component droplets, composite droplets with droplet‐to‐droplet concentration gradient, blood droplets, paired droplets, as well as bubble arrays without the need for precious flow control, a difficult task with conventional droplet microfluidics. Moreover, the self‐generated air valve can be readily deactivated (turned off) by the introduction of an oil phase, allowing for the on‐demand release of as‐formed droplets for downstream applications. It is proposed that the simple, yet versatile nature of this technique can act as an important method for droplet microfluidics and, in particular, is ideal for the development of affordable lab‐on‐a‐chip systems without suffering from scalability and manufacturing challenges that typically confound the conventional droplet microfluidics. |
| |
| Keywords: | droplet microfluidics valve immobilization point of care diagnostics |
|
|
