VATIS UPDATE Article

Scientists at Iowa State University (ISU), the United States, 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 researchers think such technology may help people charge household appliances without the need for large wind turbines. “The concept won’t replace wind turbines, but the technology could spawn a niche market for small and visually unobtrusive machines that turn wind into electricity. The possible advantages here are aesthetics and its smaller scale,” said Michael McCloskey, at ISU.

“We set out to answer the question of whether you can get useful amounts of electrical power out of something that looks like a plant. The answer is ‘possibly,’ but the idea will require further development,” added McCloskey. The ISU research team delves into the world of biomimetics, or the use of artificial means to mimic natural processes. The concept has inspired new ways of approaching fields as varied as computer science, manufacturing and nanotechnology. It’s unlikely that many people would mistake the prototype in McCloskey’s laboratory for a real tree.

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.