Micro- and Nano-Fluidic Flow in Porous Membranes

This presentation will give an overview of my dissertation work on micro- and nano-fluid transport via electro-osmosis in porous membranes. Three membrane materials were considered for this work: aluminum oxide, silicon and silicon oxide. During the course of this talk, I will touch upon the fabrication of porous aluminum oxide and porous silicon membranes followed by characterization results from all the three membranes. Of the three membranes, porous aluminum oxide and porous silicon were fabricated in-house and characterized for electro-osmotic fluid flow rate through them. While the porous aluminum oxide membrane was designed to deliver a high flow rate, the porous silicon membrane was developed as a flow rate modulation device, where flow rate can be increased or decreased via an external gate bias. I will talk about current leakage issues in the porous silicon membrane leading to an electrolytic rectification effect observed in silicon nitride thin films. The porous glass membrane constituted the third part of my thesis. This membrane was obtained commercially to measure ionic conductance in nano pores, which differs considerably from that measured in micro pores. Due to the ability to generate a high flow rate and modulate it, these membranes function as fluid flow generators that are used in micro pumps; tiny devices that find applications in the microelectronic industry for chip thermal management.