A fake tree could produce enough electric power to charge household appliances in off-grid homes without intruding on the landscape.

This take on biomimetics—the use of artificial means to mimic natural processes—harnesses piezoelectric energy generated when wind bends a specialized plastic built into the leaf stalks.

Biomimetic tree   Credit: Christopher GannonBiomimetic tree Credit: Christopher GannonMike McCloskey, associate professor at Iowa State University, says that leaves adorn some cell towers that are disguised as trees, but the leaves are only for aesthetics. He wondered if the leaves themselves could generate useful amounts of electricity.

The prototype tree consists of three metal “branches” supporting a dozen clear plastic cottonwood “leaves.” McCloskey and his team chose cottonwood leaves because their flattened leaf stalks compel blades to oscillate in a regular pattern that optimizes energy generation by flexible piezoelectric strips. The leaf stalks contain these strips. Wind blowing on the leaves causes them to move and generate electricity.

The research team set out to determine if such a device can efficiently produce enough electricity to be competitive in the market. The initial trials did produce electricity, but the fake tree was not an efficient power generator.

The team’s next step will be to find other sources of transductive electricity. Triboelectricity—generated by friction—is one candidate.

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