A passive pumping method for microfluidic devices

Abstract
The surface energy present in a small drop of liquid is used to pump the liquid through a microchannel. The flow rate is determined by the volume of the drop present on the pumping port of the microchannel. A flow rate of 1.25 μL s−1 is demonstrated using 0.5 μL drops of water. Two other fluid manipulations are demonstrated using the passive pumping method: pumping liquid to a higher gravitational potential energy and creating a plug within a microchannel.