Fast three dimensional ac electro-osmotic pumps with nonphotolithographic electrode patterning

Three dimensional (3D) stepped electrodes dramatically improve the flow rate and frequency range of ac electro-osmotic pumps, compared to planar electrodes. However, the fabrication of 3D stepped electrodes for ac electro-osmosis (ACEO) pumps usually involves several processing steps. This paper demonstrates results from ACEO pumps produced by a faster and less expensive method to fabricate the 3D electrodes-extending the previous work to disposable devices. The method is based on shadowed evaporation of metal on an insulating substrate that can be injection molded. Flow velocities through the 3D ACEO pump are similar to those seen in the previous work. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3463719]