Ever increasing energy demands, and concerns for space, energy, and materials savings highlight the necessity for miniaturized lightweight heat exchangers that can provide high heat transfer. Microchannels have superior features in this respect compared with other conventional counterparts. As such, they have significant potential for use as heat exchanger components in typical thermal and energy applications. Microchannels and Minichannels are found in many biological systems providing very high heat and mass transfer rates in organs such as the brain, lung, liver and kidney. Many high flux cooling applications are effectively utilizing their high heat transfer capabilities of these channels. Reducing passage hydraulic diameters provides a larger surface area per unit volume of heat exchangers for a given mass flux of fluid flowing through the channel.