Branching out: scientists mimic nature with electricity-generating tree

Scientists at Iowa State University have created a small-scale device which could offer an alternative to traditional wind turbines: an tree that makes electricity when its leaves blow in the wind.

The group of scientists combined piezoelectric technology – which generates electricity when plastic membranes are subjected to flex or movement –with inspiration from nature, according to the university’s website.

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Photo courtesy of Christopher Gannon

The device is inspired by the movement of tree leaves and branches in the wind and relies on piezoelectric technology to generate electricity when the artificial leaves on the device sway in the wind. The prototype tree is made up of a metal ‘trunk’ and ‘branches’ with plastic ‘leaves’.

The ‘tree’ isn’t intended to replace traditional wind turbines, but instead could offer a solution in areas where the physical footprint of a traditional turbine is undesirable.

Equally, the model could become the new standard for small-scale installations in off-grid communities, or in areas where traditional turbines are impractical.

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Photo courtesy of Christopher Gannon/Iowa State University

The device relies on the principle of biomimetics, the mimicking of natural processes using technology.

Biomimetics: the principle of mimicking natural processes using technology

The ‘tree’ is modelled specifically on the cottonwood tree, native to North America and Europe. The leaves of this particular tree are shaped in such a way that they move in a regular pattern when blown by the wind. This makes them favourable, as the resultant electricity generation is predictable and stable.

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These ‘leaves’ are made of a plastic sheet that flexes in the wind, and it’s this movement that generates electricity. This piezoelectric technology has previously been seen in a nightclub in Rotterdam – WATT nightclub, where the kinetic energy transferred by dancers to the dance floor powers the lighting beneath the transparent plexiglass dance floor.

Other research into piezoelectric technology suggests that, in the future, nano-sized generators could be installed in the screens of touch screen phones, tablets and laptops as a way of topping up the battery life of the devices when users interact with them.

Meanwhile on the UK streets, solar-powered installations are already being used for on-the-go charge points, and a Scottish company is trialling ‘kite power‘ to assist in wind power generation. While a lot of these technologies are in their early stages, and the electric tree may be a while off, it’s another small step towards integrating renewable energy into our everyday lives.