The Ohio State University has conducted a study testing the ability of high-tech objects that look like artificial trees to generate renewable power. In the recent issue of Journal of Sound and Vibration, the researchers reported that they discovered new properties in the vibrations that pass through a shaken tree-shaped object.
Ryan Harne, the project leader, started this research when he was completing his post-doctoral research at the University of Michigan. He continued this research at Ohio State University, where he is an assistant professor of mechanical and aerospace engineering and the director of the Laboratory of Sound and Vibration Research. Anqi Sun and Kon-Well Wang of the Department of Mechanical Engineering worked with Harne to continue this research and test the project.
Power Generating Vibrations
The researchers revealed that a tree-shaped structure manufactured from electromechanical materials has the ability to convert wind into strong vibrations ideal for power generation.
The researchers built a mock mechanical tree made with steel beams connected through a narrow piece of electromechanical material, polyvinylidene fluoride (PVDF). Then they started shaking the “tree” with a small amount of force from one device. They discovered that the vibrations in this process are at a high frequency and generate a minute amount of power. When the team added more force and noise to shake the “tree”, they discovered that this added force pushes the “tree” to go beyond its tipping point, producing vibrations with lower frequency – a frequency level more ideal for electricity generation.
Harne stated that this technology might be more valuable in small-scale applications or in places where windmills and solar panels are not applicable. The “trees” are simple structures with just a trunk, a few branches and no leaves. While windmills require to be put in wide open spaces, these mechanical trees are suitable in metropolitan areas, alongside bridges, and even on top of skyscrapers.
The project wants to take advantage of the amount of vibration energy from the surroundings. “Buildings sway ever so slightly in the wind, bridges oscillate when we drive on them, and car suspensions absorb bumps in the road. In fact, there’s a massive amount of kinetic energy associated with those motions that is otherwise lost. We want to recover and recycle some of that energy,” Harne said.
Even though the model and the devices were already tested, Harne, together with his colleagues, will continue to improve this project. However, the implementation of this technology lies in the hand of the government.