Iowa State University scientists have built a device that mimics the branches and leaves of a cottonwood tree and generates electricity when its artificial leaves sway in the wind. The device is derived from biomimetics, or the use of artificial means to mimic natural processes. Such biomimetic technology could become a market for those who want to generate limited amounts of wind energy without the need for tall and obstructive towers or turbines.
The device features a metallic trellis, from which hang a dozen plastic flaps in the shape of cottonwood leaves. Small strips of specialized plastic inside the leaf stalks release an electrical charge when bent by moving air. Such processes are known as piezoelectric effects. Cottonwood leaves were modeled because their flattened leaf stalks compel blades to oscillate in a regular pattern that optimizes energy generation by flexible piezoelectric strips.