Syringe-assisted point-of-care pumping

This paper presents a convient pumping method by only employing a hand held syringe. Due to the gas permeability of polydimethylsiloxane (PDMS), air trapped in the flow channel can be diffused into the surrounding vacuumed chammbers through the PDMS gaps between them. Thus after loading sample liquids, a constant flow was realized, whose flow rate can be controlled by the gap distance and overlap area between a dead-end channel and a surrounded chamber of the PDMS devices. Moreover, in order to realize a point-of-care application, the surrounded chamber was vacuumed by a hand-held syring. Therefore by pulling a syring only by hand, a constant flow rate ranging from 0.3 nl s^-1 to 4 nls^-1 was realized in our experiment.