Design of a relaying electroosmosis pump driven by low-voltage DC

Abstract

Electroosmosis pumps (EOPs) have been widely used for manipulating small amounts of reagents for chemical and biological analysis. Traditionally, a high-voltage DC has to be applied in order to achieve the required flow rate. One alternative is to use low AC voltage. Here we propose another solution, which, instead of using a high-voltage DC or low AC voltage, adds a low-voltage DC to an array of electrodes. This design of EOP is called a relaying EOP or cascade EOP. In this study, we intend to push the limit of the low-voltage further down to 2 V by patterning a dense electrode array in a straight microchannel. Two patterns of interdigitated electrodes, symmetric with equal size electrodes and asymmetric with unequal size electrodes, are proposed. Simulations are performed to optimize the distribution and geometrical parameters of the electrode array in order to achieve the maximum flow rate. The proposed low-voltage DC electroosmosis pump shows an advantage in integrating EOP into portable Lab-on-a-chip devices. In addition, the low-voltage DC EOP shows a good promise for in vivo biomedical applications such as drug delivery.