Design of Liquid-Metals Heating-Induced Temperature Gradient Focusing in Microfluidic Channels Available to Purchase

Temperature gradient focusing (TGF) is a highly efficient focusing technique for the concentration and separation of charged analytes in microfluidic channels. Design and control of an appropriate temperature gradient are very important for protein concentration and separation. In this study, we propose a new technique to generate the temperature gradient for the focusing purpose. This technique utilizes a microchannel filled with liquid-metals as a heater in the microfluidic chip. By applying electrical current, the liquid-metal microchannel generates Joule heat to form temperature gradient in the microfluidic chip. To optimize the temperature gradient, several typical designs were investigated. The results show the best design which provides the largest linear temperature gradient. The parametric studies present a clear guideline for designing aTGF microfluidic chip.