Abstract
The paper presents a novel microfluidic chip capable of continuous multi-sample switching and injection for bioanalytical applications. The innovative device integrates two important microfluidic phenomena, including hydrodynamic focusing and valveless flow switching inside multi-ported micro-channels. In this study, a theoretical model based on “flow-rate-ratio” method is first proposed to predict the performance of the microfluidic device. Then, a simple but reliable one-mask micromachining process is developed to fabricate the pre-focused MxN flow switch on a quartz substrate. The multi-sample switching and injection is then verified experimentally with the use of microscopic visualization of water sheath flows and dye-containing sample flows.