microfibre–nanowire hybrid structure for energy scavenging kiarash kiantaj 04/07/08 yong qin,...
TRANSCRIPT
Microfibre–nanowire hybrid structure for energyscavenging
Kiarash Kiantaj04/07/08
Yong Qin, Xudong Wang & Zhong Lin Wang-10.1038/nature06601
Harvesting energy from environment Solar Thermal Mechanical (wind, friction, body
movement or any environment disturbance)
Foot steps Heartbeat Air flow
Low frequency
piezoelectric zinc oxide nanowires
Kevlar fibres coated with ZnO nanowires
Hydrothermal growth TEOS (Tetraethoxysilane )
Characteristics
Single crystalline nanowires hexagonal cross-section diameter in the range ,50–200 nm length of 3.5 um Distance of few hundred nm
double-fibre model systemas nanogenerator
300 nm gold layer Schottky barrier at
Au-ZnO interface +V( reverse biased) -V (forward biased)
switching polarity testing
Ri<250Mohm Two peaks 0.2 s delay
friction-inducedelectrostatic charges
Only Au coated ZnO nanowire fibers Only ZnO nanowire fibers
Frequency range: 80-240 rpm
Improvements: Reducing the inner resistance of the fiber
Deposition of a conductive layer directly onto the fiber reduction of inner resistance to 1 k-ohm
surface contact area single yarn made of 6 fibers average current of 0.2 nA 30–50 times larger than single-fiber
Series and parallel setup
Life time
Estimation of optimum output power density from textile fabrics:20–80mW per square meter
The end
“I-V characteristic of ZnO NW coated fiber measured using the circuit as presented at the right-hand side, where silver was used as the electrodes. The inner resistance of the 4 mm fiber used here is ~ 250 MΩ.”