Charge it by 'waving'

Imagine that all you have to do to charge your ipod or blackberry is to wave your hands, stretch your arms or walk? You can say goodbye to the battery and never have to plug your electronics into the power source

In the study presented at the 237th American Medical Association in Salt Lake City, Utah on March 26, scientists from Georgia described the technology of converting mechanical energy from transport. body movement or even blood flow into electrical energy can be used to power many types of electronic devices without the need to use batteries.

Zhong Lin Wang, professor of Regents, School of Engineering and Physical Sciences at the Georgia Institute of Technology, said: 'This research will have a big impact on environmental and scientific defense and control technologies. Biomedical and even personal electronic devices'. The new 'nanogenerator' may have a multitude of applications, one of which is the running of electronic devices used by the military when away.

Scientists describe energy harvesting from the environment by shifting low frequency vibrations, such as body movement, heart beats or wind movement, into electricity, using nanowires. zinc oxide (ZnO) transmits electricity. Zinc oxide nanowires are piezoelectric - they generate electrical current when subjected to mechanical pressure. The diameter of this nanowire is 1/5000 of the diameter of a hair.

When studying energy production from motion, Wang's team concluded that the most effective way is to develop a method that works at low frequencies and is based on flexible materials. ZnO nanowires meet these requirements. An advantage of this technology is that nanowires can be created on a variety of surfaces, and nanogenerators can operate in air or in liquids. Surfaces that can create nanowires include metals, ceramics, polymers and fabrics.

Illustrative diagrams show that nanoscale nanogenerator generators are the basis for using structures to generate electricity. (Photo: Professor ZL Wang and Dr. XD Wang, Georgia Institute of Technology).

Wang said: 'Simply, this technology can be used to generate electricity in any case, just need to move'.

To this day, methods for generating nano energy are still very limited despite the growing demand of military and defense agencies for nanoscale scacs. Nanogenerators can be important for field soldiers, where there are no energy sources but still need detection and communication devices. In addition, battery-less detection devices can be very useful for air and police officers that sample air to detect terrorism with biological weapons.

While biological detectors have been scaled down and can be implanted under the skin, they still need batteries, and new nanogenerators have much greater flexibility. A major advantage of this technology is that many nanogenerators can generate electricity continuously and simultaneously. In contrast, the biggest challenge in developing these nanogenerators is to improve capacity and energy.

Wang's team has presented research on nanogenerators using ultrasound. This new study has a wider application because of the use of the lower frequency movement of the body.

The research was funded by the Defense Research Agency, the Ministry of Energy, the National Medical Institute and the National Science Foundation.