A chip scale nanofluidic pump using electrically controllable hydrophobicity

Abstract

The traditional microfluidic systems and devices faced limitations such as power consumption and high driving force in the attempt for implementation as chemical analysis and environmental monitoring systems. The up-todate development of chemistry and biology has generated great demand for lab-on-a-chip performing specific chemical and biological analysis, clinical diagnostics and biomedical processing. Manipulation of ultrasmall amount and great varieties of biofluids has also been a major issue challenging many researchers. Here we demonstrate in this article, a device utilizing electrically controllable surface tension as the driving force to deliver fluid flow in the order of nanoliters per minute or even smaller, without a dedicated actuator. This device is capable of pumping a continuous liquid column. This actuation mechanism of fluid flow in this device is based on electrowetting-on-dielectric (EWOD) effect and the physics of the fluid dynamics is governed by Navier-Stokes equation. It also has a built-in metering feature to precisely determine the flow rate without an additional flow sensor. The experimental results show that water can be electrically actuated successfully to flow in the microchannel at a flow rate of 18 nl/min under a potential of as low as 20 V. This is very attractive for applications which require an ultra miniaturized metering pump operated at a low power for portable environmental monitoring instruments, chemical analysis systems, implantable medical devices, drug delivery systems and clinical diagnostic systems. Copyright © 2009 Springer-Verlag.