Ion concentration polarization and its applications

• Main Author: Phan, Dinh Tuan
• Other Authors: Yang Chun, Charles
• Format: Theses and Dissertations
• Language: English
• Published: 2016
• Subjects: DRNTU::Engineering::Mechanical engineering::Fluid mechanics; DRNTU::Engineering::Electrical and electronic engineering::Microelectromechanical systems
• Online Access: http://hdl.handle.net/10356/66048
• Institution: Nanyang Technological University

Ion Concentration Polarization (ICP) is a fundamental electrochemical transport phenomenon that occurs when ion current passes through an ion-selective membrane in the presence of an applied electric field. Recently, ICP has attracted a great deal of attentions in microfluidic research community due to its potential applications in biological analyses and chemical species separation processes. The nature of this distinctive phenomenon is a nonlinear behavior inside the ICP region caused by the complexity of multiscale and multiphysic phenomena such as vortex formation, electroconvection instability and overlimiting conductance (OLC). Therefore from both theoretical model development and experimental investigation viewpoints, study of ICP is very important and the ICP phenomenon is still poorly understood. This study focuses on achieving a better fundamental understanding and exploring new microfluidic applications of ICP. Specifically, the thesis research first reports a novel, robust fabrication method for integrating a nanojunction inside the microfluidic device and the characterization of its working performance. Then based on such fabrication method, a new droplets-based concentrator utilizing ICP is developed and studied experimentally. Subsequently, a new platform with paper-based microfluidic device for sample concentration is reported, by using a combination of electrokinetic and ICP principles. Finally, to show more potential applications of ICP, a two-droplet generator is proposed and the mechanism for self-triggering in synchronization formation is investigated.