Protocol for growing silica nanowires on various substrates to enhance superwetting and self-jumping properties.

The protocol outlines the steps for growing silica nanowires on various substrates such as glass and stainless-steel foil. Silica nanowires are grown by thermal chemical vapor deposition via a vapor-liquid-solid mechanism, in which silicon wafers are used as silicon sources and platinum films as catalysts. This protocol can be used to grow silica nanowires on other substrates such as quartz filter, quartz sphere, alumina plate, and silicon wafer, provided the substrate materials can tolerate the temperature during process heating. For complete details on the use and execution of this profile, please refer to Lee et al. (2019), Tsai and Shieh (2019), and Tsai et al. (2021).

Harvesting water surface energy: self-jumping nanostructured hydrophobic metals.

Water in motion is a significant energy source worldwide, but the surface energy of water is rarely utilized as a power source. In this study, we made metals unsinkable and able to jump out of the water by harvesting the water surface energy. This effect is attributed to the enhanced floating ability of the nanostructures on copper and stainless steel foil surfaces. Sufficiently thin hydrophobic metals can slowly float underwater through air trapping at the surface and then rapidly leap out of the water on contact with the water-air interface. The mechanism is related to the surface energy of the water, which contributes to the 15 mg metals with a power of 0.49 µW experiencing rapid changes in velocity and acceleration at the interface. The conversion of surface energy to eject nanostructured hydrophobic materials from the liquid surface may lead to new solid-liquid separation techniques.