This work presents design, fabrication and optimization of methanol concentration and flow channel cross-sectional geometry for enhanced power output in passive micro-direct methanol fuel cells. Passive micro-direct methanol fuel cells are fabricated with flow channels in silicon having both rectangular and trapezoidal cross-sectional geometry for flow of methanol at anode and air at cathode using microelectromechanical systems (MEMS) fabrication technique. The experiments are conducted at 25 °C by feeding methanol with a flow rate of 25 μl min −1 and supply of air at cathode by air-breathing method. Results show a peak in open circuit voltage and power density at 7 M methanol concentration for passive micro-direct methanol fuel cells having both rectangular and trapezoidal cross-sectional geometry. A study of influence of silicon flow channel cross-sectional geometry on passive micro-direct methanol fuel cell performance shows for the first time that the flow channels with trapezoidal cross-section enhance the power density (6.64 mW cm −2 ) nearly by a factor of two compared to that of flow channels with rectangular cross-section (3.9 mW cm −2 ) at 7 M methanol concentration.We believe that, though our results of significant enhancement of power density with trapezoidal fuel flow channels are obtained with micro-direct methanol fuel cells as a platform, they should also be applicable to other proton exchange membrane fuel cells with ethanol or humidified hydrogen as fuel.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.