Abstract: Methods of forming hydrophobic surfaces or structures include spraying droplets of a material onto features on a surface of a substrate and at least partially coating the features with a material formed from the droplets. Methods of forming fuel or electrolytic cells include forming a plurality of features in a surface of a conductive plate within a channel therein, and configuring the surface of the conductive plate within the channel to be hydrophobic. Additional methods of forming fuel or electrolytic cells include forming a substrate having a surface comprising at least one channel therein, forming a plurality of features on a surface of the substrate within the at least one channel, spraying droplets of a material onto the substrate, and at least partially coating the features with a metal layer formed from the droplets. Hydrophobic structures such as, for example, conductive electrodes for fuel and electrolytic cells are fabricated using such methods.

Abstract: A system for and method of manufacturing a finned tube for a heat exchanger is disclosed herein. A continuous fin strip is provided with at one pair of vortex generators. A tube is rotated and linearly displaced while the continuous fin strip with vortex generators is spirally wrapped around the tube.