Flexibly driving micro flow in a Lab-on-Chip system via dry porous structure

摘要

This paper is dedicated to present a low cost way for flexibly driving micro flow in a Lab-on-Chip system through utilizing the wetting mechanism. The unique merit of the method lies in its intentional employment of the wettability between liquid and the dry porous structure. The device thus fabricated only constitutes with a piece of dry porous material and a micro tube filled with liquid. When starting driving, connecting the objective liquid to the micro tube with pre-filled liquid at the entrance; then attaching the dry material to the exit end of the micro tube. Due to wettability between the pre-filled liquid and the dry material, the volume of the pre-filled liquid would decrease which subsequently induce a pressure reduction in the micro tube. As a result, the objective liquid will be jammed into the micro tube by the atmospheric pressure. With this working principle, the driving device is provided with several advantages such as being simple, cheap, safe, and clean; it also owns a wide range of applications in micro fluidics analysis. Theoretical interpretation and demonstration experiments were performed to evaluate the working performances of the driving device. Several factors liable to affect the running state of the driving device have been proposed and evaluated. It has been proved that this driving device is highly feasible and can be adopted as a micro pump for disposable Lab-on-Chip.