A novel pinched-switching T-form mixer for fast DNA digestion

This paper presents a novel microfluidic T-form mixer for fast DNA digestion utilizing alternatively switching electroosmotic flow. A switching DC field is used to generate an electroosmotic force which simultaneously drives and mixes the fluid samples. A novel pinched-switching mode is presented for fast DNA and restriction enzyme mixing in the microfluidic device. Experimental and numerical results show that a mixing performance as high as 97% can be achieved within a mixing distance of 1 mm downstream from the T-junction when a 90 V/cm driving voltage and a 4 Hz switching frequency are applied. Successfully digestion of λ-DNA using ECORI restriction enzyme is demonstrated utilizing the proposed microdevice. The novel T-form micromixer presented in this study provides a simple solution to mixing problems in the micro-total-analysis-systems field.