Stories tagged Georgia Tech

I'm on a roll, now. Science Friday
Science FridayCourtesy Science Friday
"Water striders don't really stride, they row on the water. But their legs are spindly and don't seem good for paddling. David Hu, mechanical engineer at Georgia Tech, wanted to understand the basic physics of how water striders glide. By filming them stride on food coloring and building his own robotic strider, he found out that the secret to the stride is in the paddle."
It's Friday, so it's time for a new Science Friday video. Science Friday
Science Friday
Courtesy Science Friday
This week,
"Pumpkins of the Atlantic Giant variety can weigh more than 1800 pounds. For a mechanical engineer with an interest in plus-sized fruit, like Georgia Tech’s David Hu, this raises an interesting physics question: how can the pumpkin get so big without breaking?"

Jewel  bug colors
Jewel bug colorsCourtesy arquera
Georgia Tech scientists provided a detailed explanation of how the jeweled beetle Chrysina gloriosa creates the striking colors using a unique helical structure that reflects light of two specific colors.

A cholesteric liquid crystalline material, which self-assembles into a complex arrangement of polygonal shapes each less than 10 microns in size, causes interference within reflected light resulting in bright green light with a wavelength of 530 nanometers mixed with yellow light in a wavelength of 580 nanometers.

Learn more by reading this Georgia Tech news release.

Graphene is again proving to be the super material. Micro ribbons of graphene are out performing copper wires, both in current carrying capacity and in heat dissipation.

In widths as narrow as 16 nanometers, graphene has a current carrying capacity approximately a thousand times greater than copper – while providing improved thermal conductivity. Georgia Tech

Feb
15
2008

Rubs you the right way: This microscope image shows the fibers that are part of the microfiber nanogenerator. The top one is coated with gold. When rubbed together, the wires create a low amount of electricity. (Image courtesy Zhong Lin Wang and Xudong Wang).
Rubs you the right way: This microscope image shows the fibers that are part of the microfiber nanogenerator. The top one is coated with gold. When rubbed together, the wires create a low amount of electricity. (Image courtesy Zhong Lin Wang and Xudong Wang).Courtesy Georgia Tech
This sounds like some bad leftover from the disco era -- remember that cheesy movie "Electric Horseman? But scientists at Georgia Tech have developed an electricity-generating fabric that we might someday soon be wearing.

The new cloth would create enough electricity through normal living activities to power up an iPod or similar electrical device. To be more specific, one meter of the fabric would create 80 milliwatts of electricity.

How can this happen?

The fabric has ultra-thin wires woven into it. Wires going one direction are coated with zinc oxide while wires aligned in the other direction are treated with gold. When rubbed together through everyday movement of the wearer, they create electricity that can be fed into a current. In scientific terms, this technology is known as the piezoelectric effect.

Powerline: This schematic shows how pairs of fibers would generate electrical current.
Powerline: This schematic shows how pairs of fibers would generate electrical current.Courtesy Georgia Tech
The wires are only 50 nanometers in thickness, or about 1,800 times thinner than a strand of your hair. Because of this microscopic size, designers figure that the wires won’t create any substantial extra weight to clothes made of the fabric. Also, designers believe they’ll be able to use other cheaper metals to get the same electricity-generating effect.

Along with being used in clothes to generate small amounts of electricity, researchers can see other applications for the technology. The fibers could also be woven into curtains, tents or other structures to capture energy from wind motion, sound vibration or other mechanical energy.

There is one huge drawback. So far developers haven’t figured out how to make the fabric waterproof. That’s a major consideration when you realize that owners of the clothes at some point will want to wash it or wear it while it’s raining.

Want all the juicy details of this latest technology? Here’s a link to Georgia Tech’s full report on piezoelectric fabrics.