Electric-field-induced Droplet Dispensing for Electrically Controllable Microparticle Fabrication and Droplet Manipulation

다국어 초록 (Multilingual Abstract)

Dispensing of tiny droplets is a basic and crucial process in myriad biochemical applications, such as DNA/protein microarray, cell cultures, chemical synthesis of microparticles, and digital microfluidics. This work demonstrates droplet dispensing on immiscible fluids through electric charge concentration (ECC) as a function of flow rates, applied voltages, and gap distances between the nozzle and the surface of oil, exhibiting three main modes (i.e., attaching, uniform, and bursting modes). Through a conventional nozzle with diameter of a few millimeters, charged droplets with volumes ranging from a few μL to a few tens of nL can be uniformly dispensed into the oil chamber without reduction in nozzle size. Based on the fascinating features of the proposed method (e.g., formation of droplets with controllable polarity and amount of electric charge in water and oil system), a simple and straightforward method is developed for microparticle synthesis, such as preparation of colloidosomes and fabrication of anisotropic Janus microparticles. Finally, a combined system consisting of ECC-induced droplet dispensing and electrophoresis of charged droplet (ECD)-driven manipulation systems is constructed. This integrated platform will provide more utility and flexibility in biochemical applications because a charged droplet can be delivered toward the intended position by programmable electric control.

목차 (Table of Contents)

• Abstract
• 1. Introduction
• 2. Experimental details
• 3. Results and discussion
• 4. Conclusion
• References