The interesting device, inspired by nature to produce renewable energy, has been designed at Iowa State University. The technology consists of small strips of bespoke plastic fitted inside the leaf stalks. These fittings release an electrical charge when they are folded or bent by moving air. The science behind this is called the ‘piezoelectric effect’ (or biomimetic technology). The piezoelectric effect is the ability of certain materials to generate an electric charge in response to applied mechanical stress.
For the nature inspired part, the scientists looked to the cottonwood tree. This was because the leaves have flattened leaf stalks. When applied to the design these direct blades to oscillate in a regular pattern that optimizes energy generation. In other words, the natural design of this type of tree’s leaves are the most efficient for electrical generation. Cottonwood trees are large, deciduous trees 20–45 meters tall, distinguished by thick, deeply fissured bark and triangular-based to diamond-shaped leaves.
The device will not be powerful enough to replace wind turbines, but it can produce sufficient power for a home or a small workplace (wind turbines still have a future in Trump’s U.S., as Digital Journal’s Karen Graham has recently reported). It is hoped the construct will find a niche market, perhaps in areas where there is an adverse reaction to monolithic wind turbines.
Behind the device is Professor Michael McCloskey. He tells Controlled Environments more about the potential applications: “The possible advantages here are aesthetics and its smaller scale, which may allow off-grid energy harvesting.”
The researcher continues: “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.”
One answer is the aesthetics used to disguise mobile phone masts. In more picky neighbourhoods, unsightly cell phone masks have been disguised with real or artificial trees. Professor McCloskey thinks that his device can be incorporated into the mast camouflage, helping to generate low cost power while obscuring what some consider to be a modern world eyesore.
The research and device description have been published in the journal PLOS ONE. The research paper is headed “Wind Energy Conversion by Plant-Inspired Designs.”
