Harnessing Waves with Nanostructured Hydrophobic Surface

The American Chemical Society has published a paper on a new way to harvest wave energy.

Beijing Institute of Nanoenergy and Nanosystems at Chinese Academy of Sciences and School of Materials Science and Engineering at Georgia Institute of Technology gave their contribution to this report, which looks into liquid–solid electrification-enabled generator based on a fluorinated ethylene propylene thin film, below which an array of electrodes are fabricated.

The surface of the thin film is charged first due to the water–solid contact electrification.

Aligned nanowires created on the thin film make it hydrophobic and also increase the surface area. Then the asymmetric screening to the surface charges by the waving water during emerging and submerging processes causes the free electrons on the electrodes to flow through an external load, resulting in power generation.

The generator produces sufficient output power for driving an array of small electronics during direct interaction with water bodies, including surface waves and falling drops. Polymer-nanowire-based surface modification increases the contact area at the liquid–solid interface, leading to enhanced surface charging density and thus electric output at an efficiency of 7.7%.

This generator, with no movable components, could also be used in large-scale energy generation if layers of planar sheets are connected into a network.