Miniaturization technologies for advanced energy conversion and transfer systems

Microfabrication technologies have made possible the development of meso-scale energy conversion and chemical processing systems with microscale features, Scaling effects, such as the linear increase in surface-area-to-volume ratio that affects surface processes such as convection heat transfer, adsorption, and catalytic chemical conversion processes, provide some of the motivation for the miniaturization efforts. Other mechanical, thermal, and fluid scaling effects are presented. Fabrication and material limitations, as well as scaling effects, must be considered in the design process and may result in miniaturized systems that are considerably different than their full-scale prototypes, System and component development efforts at Battelle Pacific Northwest National Laboratories are highlighted. A fuel atomizer for gas turbine engines and a multicomponent fuel processor for the production of on-demand hydrogen are microscale components that show potential for improving current large-scale systems. Complete miniaturized systems such as a gas turbine, a vapor-absorption heat pump, and a Joule-Thompson cryocooler could be used for mobile power production and cooling of electronics and individuals. Components for miniaturized systems include microbatteries with multiple definable voltage levels and a high degree of integratability and a combustor/evaporator for methane combustion with low levels of harmful emissions.