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Microfiber-NanowireHybrid Structure for Energy Scavenging
by Y. Qin, X.D. Wang and Z.L. Wang Nature, 451 (2008) 809-813. (Supplementary materials)
 Abstract: A self-powering nanosystem that harvests its operating energy
from the environment is an attractive proposition for sensing,
personal electronics and defence technologies1. This is in principle
feasible for nanodevices owing to their extremely low power
consumption2–5. Solar, thermal and mechanical (wind, friction,
body movement) energies are common and may be scavenged
from the environment, but the type of energy source to be chosen
has to be decided on the basis of specific applications. Military
sensing/surveillance node placement, for example, may involve
difficult-to-reach locations, may need to be hidden, and may be
in environments that are dusty, rainy, dark and/or in deep forest.
In a moving vehicle or aeroplane, harvesting energy from a rotating
tyre or wind blowing on the body is a possible choice to power
wireless devices implanted in the surface of the vehicle. Nanowire
nanogenerators built on hard substrates were demonstrated for
harvesting local mechanical energy produced by high-frequency
ultrasonic waves6,7. To harvest the energy from vibration or disturbance
originating from footsteps, heartbeats, ambient noise
and air flow, it is important to explore innovative technologies
that work at low frequencies (such as ,10 Hz) and that are based
on flexible soft materials. Here we present a simple, low-cost
approach that converts low-frequency vibration/friction energy
into electricity using piezoelectric zinc oxide nanowires grown
radially around textile fibres. By entangling two fibres and
brushing the nanowires rooted on them with respect to each
other, mechanical energy is converted into electricity owing to
a coupled piezoelectric–semiconductor process8,9. This work
establishes a methodology for scavenging light-wind energy and
body-movement energy using fabrics.
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MRS Bulletin, 2007, 32 (2)
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