Fluttering leaves could be one day generate electricity

The quest for clean energy alternatives may soon include the ability to harvest energy from leaves shifting in the wind.

Researchers from the Laboratory of Organic Electronics at Linköping University have discovered a way to power a small electric circuit using the fluctuations between sun and shade, similar to a leaf fluttering in the wind.

Although the technology is in its early stages, the study shows that heat fluctuations from sunlight to shade can be converted into energy.

“Plants and their photosynthesis systems are continuously subjected to fluctuations between sunshine and shade,” said Magnus Jonsson, an author of the study. “We have drawn inspiration from this and developed a combination of materials in which changes in heating between sunshine and shade generate electricity.”

The study was published in the journal Advanced Optical Materials.

Previously, Magnus Jonsson had worked on a project that developed small nanoantennas made up of gold nanodiscs with the ability to absorb sunlight and generate heat by reacting to near-infrared light.

In this new study, the nanoantennas powered a tiny optical generator using pyroelectric film. Pyroelectric means that power is generated from changes in heat.

As the antennae were subjected to fluctuations in sunlight and shade, they generated heat which was then converted to electricity.

“The nanoantennas can be manufactured across large areas, with billions of the small discs uniformly distributed over the surface,” said Jonsson. “The spacing between discs in our case is approximately 0.3 micrometres. We have used gold and silver, but they can also be manufactured from aluminium or copper.”

A polarized polymer was also required for energy conversion.

“We force the polarisation into the material, and it remains polarised for a long time, “ said Mina Shiran Chaharsoughi, the lead author of the study.

The researchers tested their theory with experiments and computer simulations. In one of the experiments, a twig with leaves in front of a fan powered a small external circuit.

The study has many exciting applications and result in another dependable source of renewable energy.

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By Kay Vandette, Earth.com Staff Writer