Numerical Simulation of Thermal Diffusion and Convection in Electrokinetic Microchannel Flow

Abstract

: In a confined microfluidic straight channel with one heater and two detectors micro-fabricated on suspended silicon bridges, the numerical study of thermal diffusion and convection in electro-osmosis flow was carried out. Heat pulses created by the heater are transported downstream by the flow, and by performing a cross correlation between the detected and the injected signals, the linear relation between flowrate and thermal pulse's time-of-flight can be achieved, then it can provide a very accurate a linear measurement of the flowrate over long range without independence of the thermal characteristics of the fluid. These conclusions may be helpful to integration of accurate flowmeter in some portable electrokinetic micro-total-analysis systems. Key words: Electroosmosis; Thermal-pulse; Time-of-flight; Micro-flowmeter