Micro fuel cells are candidate power sources of high energy density for portable applications. The microfabrication and characterization of silicon-based fuel cells, in which key components including the flow fields, current collector, and catalyst support structures are integrated onto a single chip, were presented. The optimization of electrodeposited catalyst structures for Si-based micro fuel cells, and efforts to minimize the parasitic losses during fuel cell operation were described. A novel laminar flow-based fuel cell (LF-FC) was presented. The use of laminar flow in a fuel cell eliminates the need for a proton-conducting membrane. These LF-FC studied to date exhibit severe cathodic limitations due to poor solubility of oxygen in aqueous media. Methods to overcome mass transfer related limitations at the cathode to improve the performance of LF-FC were reported. This is an abstract of a paper presented at the AIChE Annual Meeting and Fall Showcase (Cincinnati, OH 10/30/2005-11/4/2005).