Harvesting energy from “vibrations”

[LuisP]

On June 15, 2011, the “American Chemical Society” press-released this :
Scientists are reporting development of the first self-powered nano-device that can transmit data wirelessly over long distances and that operate independently without batteries on energy collected from the environment.
Zhong Lin Wang and colleagues explain that advances in electronics have opened the door to developing tiny devices that operate battery-free on minute amounts of electricity that can be harvested from the pulse of a blood vessel, a gentle breeze, or the motions of a person walking.
“It is entirely possible to drive the devices by scavenging energy from sources in the environment such as gentle airflow, vibration, sonic wave, solar, chemical, and/or thermal energy,” the scientists explain.
The device consists of a nanogenerator that produces electricity from mechanical vibration/triggering, a capacitor to store the energy, and electronics that include a sensor and a radio transmitter similar to those in Bluetooth mobile phone headsets. Their device transmitted wireless signals that could be detected by an ordinary commercial radio at distances of more than 30 feet.

Full article here : http://www.acs.org/content/acs/en/press ... ssion.html

On November 15, 2012, the “Stony Brook University” press-released this :
A Stony Brook University team of engineers developed a new type of energy harvester that converts the irregular, oscillatory motion of train-induced rail track vibrations into regular, unidirectional motion, in the same way that an electric voltage rectifier converts AC voltage into DC
They called it the "Mechanical Motion Rectifier (MMR) based Railroad Energy Harvester" and say it can harness 200 watts of electric energy from train-induced track deflections to power the track-side electrical devices.
By using two one-way clutches, the innovative mechanical motion rectifier converts the irregular up-and-down vibration motion into unidirectional rotation of the generator, thus breaking the fundamental challenge of vibration energy harvesting and offering significant advantages of high efficiency and high reliability."
Professor Zuo and his team have been working on vibration and thermoelectric energy harvesting in the past several years to harness power from different sources, including trains, cars, tall buildings and ocean waves.

Full article here : http://commcgi.cc.stonybrook.edu/am2/pu ... ions.shtml

On February 20, 2014, the “University of Wisconsin-Madison” press-released this :
A multi-university team of engineers has developed what could be a promising solution for charging smartphone batteries on the go -- without the need for an electrical cord.
The team's described their device as a mesoporous piezoelectric nanogenerator in the January 27, 2014, issue of the journal Advanced Energy Materials, and say it can harvest and convert vibration energy from a surface, such as the passenger seat of a moving vehicle, into power for the phone.
Piezoelectric materials can generate electricity from a mechanical force; conversely, they also can generate a mechanical strain from an applied electrical field.
Rather than relying on a strain or an electrical field, the researchers incorporated zinc oxide nanoparticles into a PVDF thin film to trigger formation of the piezoelectric phase that enables it to harvest vibration energy. Then, they etched the nanoparticles off the film; the resulting interconnected pores - called "mesopores" because of their size - cause the otherwise stiff material to behave somewhat like a sponge.
The simplicity of his team's design and fabrication process could scale well to larger manufacturing settings. "We can create tunable mechanical properties in the film," they say.

Full article here : http://www.news.wisc.edu/22578