Application of droplet reactors with microfluidics

Abstract

In droplet microfluidics, droplets act as individual reactors when chemical and biological reactants are encapsulated. To perform reactions and fabricate materials, droplet reactors need to be generated and manipulated. A tremendous amount of droplet generation and manipulation techniques have been developed, such as droplet coalescence and droplet injection, extending the applications of droplet reactors to material fabrication and bio(chemical) analysis. However, few techniques are capable of generating droplets with tunable components in large quantities, this is of great importance in various areas such as reaction condition screening and multi-compartmental particle fabrication. To address this issue, we propose four techniques to generate a large number of droplets with tunable components, contributing to material fabrication and pathogen detection. Specifically, in Chapter 3, we develop a phase separation-induced droplet generation technique, producing Janus droplets with tunable compartment ratios. The resultant Janus droplets are applied in fabricating non-spherical particles and encapsulating bio-ingredients with preserved bioactivity. In Chapter 4, we propose a segmented picoinjection method to generate droplets with tunable reactants to detect multiple pathogens based on droplet loop mediated-isothermal amplification (dLAMP) technique. In Chapter 5, we propose an electricity-free injection method to inject reactants with tunable volume into flowing droplets, applying in synthesizing nanoparticles and crystals exhibiting narrow size distribution. In Chapter 6, we propose a novel system to generate droplets in large quantities by applying negative pressure. The resultant droplets are applied to simultaneously performing multiple dLAMP reactions to detect pathogens. In summary, this dissertation focuses on developing techniques to generate droplets with tunable components in large quantities. These developed techniques are applied in material fabrication and bio(chemical) analysis. These advanced techniques extend the application of droplet reactors for tackling real-world issues, such as preserving the bioactivity of the encapsulated ingredients, synthesizing monodispersed materials and detecting pathogens.