Lipids: Source of Static Electricity of Regenerative Natural Substances and Nondestructive Energy Harvesting.

It is familiar to everyone that human skin and hair easily lose electrons and cause static electricity as they undergo friction with other materials. Such natural regenerative substances take a high ranking in the triboelectric series. Even though the static electricity of regenerative natural substances has been a long-term curiosity in human history, it is not yet clear which of their components causes the positive static charges. This study reveals that lipid layers on the surface of regenerative substances (skin, hair, leaves, cells) and even synthetic lipids are responsible for this positive static electricity and shows that it is possible to manufacture lipid-based triboelectric nanogenerators (TENGs). Using the characteristic that lipids on leaves regenerate within a few hours, lipids from living tree leaves are collected, and lipid-based nondestructive TENGs are fabricated. The concept of energy-harvesting vines is also presented, which can generate electricity when they are wrapped loosely on living tree branches. This study suggests how to harvest electricity while preserving nature as it is.