Aluminum-anode, silicon-based micro-cells for powering expendable MEMS and lab-on-a-chip devices

On-demand powering via micro-fluidic actuation of electrolyte in voltaic cells has been introduced as an alternative to power disposable MEMS-based sensor systems. Aluminum-anode cells activated with alkaline-hydrogen peroxide electrolyte mixtures are studied with the aim of achieving high energetic densities relative to the cells' minute dimensions. Cells with two configurations are fabricated and their performance is investigated here. The cells have an open-circuit potential of 1.4 and 1.8 V, depending on the electrolyte used for activation. Potential under various electrical loads are presented as a performance evaluate. An assessment of the influence of cell configuration and electrolyte chemistry on the gravimetric aluminum utilization for energy production on the tested micro-cells is also presented. A gravimetric aluminum utilization efficiency (GAIUE) is defined to indicate the actual energy produced per gram of deposited aluminum relative to the theoretical amount, to compare the performance of the cells. The fabricated cells performance is compared with alkaline commercial cells and it is found that they have good gravimetric energy densities and high specific power, relative to their sizes. GAIUE-values between 33 and 87% were found for cells that provided power outputs of 16 and 5 mW, respectively, for periods between 5 and 6 min. Longer operational times (up to 45 min) at a potential equal to 1.61 V, are possible while the cells provide smaller power values (0.5 mW). (c) 2006 Elsevier B.V. All rights reserved.