Gizmorama - February 8, 2016
Good Morning,
Here's a story that will blow your mind. It seems that mechanical trees have been created to generate power as they sway in the wind. That's alternative energy for you.
Learn about this and more interesting stories from the scientific community in today's issue.
Until Next Time,
Erin
P.S. Did you miss an issue? You can read every issue from the Gophercentral library of newsletters on our exhaustive archives page. Thousands of issues, all of your favorite publications in chronological order. You can read AND comment. Just click
GopherArchives
***
*-- Mechanical trees generate power as they sway in the wind --*
COLUMBUS, Ohio - Most tall objects, whether natural or man-made, sway in the wind -- buildings, trees, bridges. Researchers at Ohio State are trying to find a way to turn all that kinetic energy into electricity.
And according a new paper published in the Journal of Sound and Vibration, they've had a breakthrough of sorts.
They developed electromechanical materials capable of converting sporadic energy, like gusts of wind, into electricity-producing structural vibrations. The scientists say these materials could be used to build treelike structures -- a short trunk with a few branches.
Lead researcher Ryan Harne, assistant professor of mechanical and aerospace engineering at Ohio State, says the technology's initial applications are likely to be modest -- a small mechanical tree powering a sensor that monitors the structural health and integrity of a bridge or building.
But there is the potential to scale up.
"Buildings sway ever so slightly in the wind, bridges oscillate when we drive on them and car suspensions absorb bumps in the road," Harne said in a news release. "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."
The key to the new technology is the material's ability to turn high-frequency inputs, random gusts of wind, into consistent low-frequency vibrations that can generate power. The researchers used a model to determine the proper structure. A tree-like shape was ideal for promoting the kind of internal resonance they needed.
The swaying motion of their prototype confirmed what their model predicted. With sufficient external input, the swaying tree reached what the researchers call "saturation phenomena," converting high-frequency forces into low-frequency oscillation.
"In addition, we introduced massive amounts of noise, and found that the saturation phenomenon is very robust, and the voltage output reliable," Harne said. "That wasn't known before."
*-- Scientists develop world's smallest lattice structure --*
KARLSRUHE, Germany - Researchers at Germany's Karlsruhe Institute of Technology, or KIT, have built the world's tiniest lattice structure using glassy carbon struts and braces.
Though the components measure less than 200 nanometers in diameter and just a single micrometer in length, the resulting structure boasts a higher specific strength than most solids.
Described in the latest edition of Nature Materials, the 3D lattice structure is five times smaller than the closest comparable nanomaterials and features an unparalleled strength-to-density ratio.
"Lightweight construction materials, such as bones and wood, are found everywhere in nature," lead study author Jens Bauer, said in a news release. "They have a high load-bearing capacity and small weight and, hence, serve as models for mechanical metamaterials for technical applications."
The tiny structure is assembled via 3D laser lithography technology and then hardened using a laser-based material known as a photoresist.
Next, the structure is shrunk using a process called pyrolysis. When the structure is exposed to temperatures upwards of 900 degrees Celsius in a vacuum furnace, all elements but carbon escape as the chemical bonds reorient themselves.
What's left is an even smaller lattice structure in the form of glassy carbon.
"According to the results, the load-bearing capacity of the lattice is very close to the theoretical limit and far above that of unstructured glassy carbon," said study co-author Oliver Kraft. "Diamond is the only solid having a higher specific stability."
Microsctructures are often employed in insulation or for shock absorption, but researchers say the new lattice structure could also be used in electrodes, filters or optical components.
***
Missed an Issue? Visit the Gizmorama Archives