Depending on where you are in the world, the sun rises on one side, moves up, over your head, then sunsets down on the opposite side. Therefore, the light is always moving, and if you depend on it to generate power, then you might experience oblique-incidence energy-density loss.

To remedy this issue, researchers from the University of California Los Angeles and Arizona State University, have designed solar panels made from rows of tiny artificial sunflowers. The sunflowers automatically bend towards the light, allowing it to harvest a significant amount of solar power. This behavior is much like in nature, real sunflowers tilt their flowers to face the sun, heating their reproductive bits to attract pollinators.

This system could potentially be a solution for almost any system that experiences efficiency loss due to a moving energy source. For example, with rays from an overhead illumination source, the light coming in at an angle of around 75 degrees carries up to 75% less energy.

The researchers, Ximin He, and her colleagues say their system is a sunflower-like biomimetic omnidirectional tracker, dubbed ‘SunBOT.’ Each artificial sunflower has a stem made up of a material that reacts to light. An energy harvesting flower, made from a light-absorbing material used in solar cells, sits at the top of the stem. Each SunBOT is measured less than 1 millimetre wide.

When a part of the SunBOT’s stem gets exposed to light, it heats up and shrinks, causing it to bend and lean towards the light. Once the SunBOT is aligned with the light, the bending stops because the flower creates a shadow that gives the material time to cool down and stop shrinking.

The team tested the artificial sunflower to detect its harvesting capabilities by building a panel of SunBOTs, some of which possessed the bendy material and some that didn’t. The researchers found that the SunBOTs with the bendy-stems harvested up to 400% more solar energy than the non-bendy stemmed ones.

SunBOTs’ creators explain:

“This work may be useful for enhanced solar harvesters, adaptive signal receivers, smart windows, self-contained robotics, solar sails for spaceships, guided surgery, self-regulating optical devices, and intelligent energy generation, as well as energetic emission detection and tracking with telescopes, radars, and hydrophones.”

It seems the possibilities are endless with this new kind of technology! The researchers describe their study in Nature Nanotechnology.

Please SHARE this article with your family and friends.