Introducing a Digital Micropump for Driving a Droplet in a Microfluidic Channel

H. Rezaei Nejad, M. Paknahad, M. Hoorfar
University of British Columbia, CA

Keywords: micropump, digital microfluidics, droplet, transport


This paper presents a novel pumping technique which is compatible with both digital and continuous microfluidic platforms. In essence, a target droplet (referred to as the pumped droplet) is pumped by actuating the secondary droplet (referred to as the piston droplet) in a microfluidic channel using the electrowetting on dielectric (EWOD) method. The pumping technique presented was tested experimentally. It is shown that the movement of the pumped droplet in the channel can accurately be controlled by manipulating the piston droplet. The actuation signal of the piston droplet can precisely be controlled to create the desired transport rate for the pumped droplet. Silicon oil was used as the filler medium to reduce friction and improve sealing of the channel. It is observed that the shape of the pumped droplet during pumping does not change which suggests that the velocity profile after pumping is a plug flow velocity profile.