Seminar in SMMEE: Propagation and Interaction of Ion Concentration Shock Waves in Microfluidics

Title: Propagation and Interaction of Ion Concentration Shock Waves in Microfluidics
Speaker: Dr. Supreet Singh Bahga
Location: L2
Date: 09-Apr-2013 (Tue)
Time: 2:00pm - 3:00pm

Abstract:

Microfluidics lies at the interface between engineering, chemistry, and biology, and aims todevelop “lab-on-a-chip” type systems for analysis of complex biological and chemical mixtures.Many of these microfluidic systems are based on separation of ionic species by electrokinetictransport. Nonlinearities associated with such electrokinetic processes can result in formation ofshock and rarefaction waves in ion-concentrations. We here focus on an electrokinetic techniquecalled isotachophoresis (ITP), wherein propagating shock waves form between regions of high andlow mobility ions. Depending on the charge of ions, these shocks can propagate either towardsanode or cathode, and may interact with each other. My talk will focus on both simulations andexperiments of these propagating and interacting shocks waves. First, I will present development,formulation and experimental validation of a fast and stable simulation code to simulate theseshock waves. I will then discuss simultaneous anionic and cationic ITP process, in which shockwaves approach each other and then interact. Based on simulations and experiments, I will discuss how the interaction of these shock waves can be applied to couple different electrokinetic processesfor high sensitivity detection of variety of species, including DNA fragments and environmentaltoxins.