Device captures energy from walking to
recharge wireless gadgets
New device harnesses the energy created by
natural human walking.
Credit and Larger Version
July 1, 2014
Editor's Note: This Behind the Scenes article was
first provided to LiveScience in partnership with
the National Science Foundation.
By the end of 2014, Earth will be home to more
mobile electronic devices than people .
Smartphones, tablets, e-readers, not to mention
wearable health and fitness trackers, smart
glasses and navigation devices--today's
population is more plugged in than ever before.
But our reliance on devices is not problem-free:
1. Wireless gadgets require regular recharging.
While we may think we've cut the cord, we
remain reliant on outlets and charging
stations to keep our devices up and
running.
2. According to a 2009 report by the
International Energy Agency (IEA),
consumer electronics and information and
communication technologies currently
account for nearly 15 percent of global
residential electricity consumption. What's
more, the IEA expects energy consumptions
by these devices to double by 2022 and to
triple by 2030--thereby slowly but surely
adding to the burden on our power
infrastructure.
With support from the National Science
Foundation, a team of researchers at the
Georgia Institute of Technology may have a
solution to both problems: They're developing a
new, portable, clean energy source that could
change the way we power mobile electronics:
human motion.
Led by material scientist Zhong Lin Wang, the
team has created a backpack that captures
mechanical energy from the natural vibration of
human walking and converts it into electrical
energy. This technology could revolutionize the
way we charge small electronic devices, and
thereby reduce the burden of these devices on
non-renewable power sources and untether
users from fixed charging stations.
Smaller, lighter, more energy efficient
Wearable generators that convert energy from
the body's mechanical potential into electricity
are not new, but traditional technologies rely on
bulky or fragile materials. By contrast, Wang's
backpack contains a device made from thin,
lightweight plastic sheets, interlocked in a
rhombic grid. (Think of the collapsible cardboard
containers that separate a six pack of fancy soda
bottles.)
As the wearer walks, the rhythmic movement
that occurs as his/her weight shifts from side to
side causes the inside surfaces of the plastic
sheets to touch and then separate, touch and
then separate. The periodic contact and
separation drives electrons back and forth,
producing an alternating electric current. This
process, known as the triboelectrification effect,
also underlies static electricity, a phenomenon
familiar to anyone who has ever pulled a freshly
laundered fleece jacket over his or her head in
January.
But the key to Wang's technology is the addition
of highly charged nanomaterials that maximize
the contact between the two surfaces, pumping
up the energy output of what Wang calls the
triboelectric nanogenerator (TENG).
"The TENG is as efficient as the best
electromagnetic generator, and is lighter and
smaller than any other electric generators for
mechanical energy conversion," says Wang. "The
efficiency will only improve with the invention of
new advanced materials."
Charging on the go
In the laboratory, Wang's team showed that
natural human walking with a load of 2
kilograms, about the weight of a 2-liter bottle of
soda, generated enough power to
simultaneously light more than 40 commercial
LEDs (which are the most efficient lights
available).
Wang says that the maximum power output
depends on the density of the surface
electrostatic charge, but that the backpack will
likely be able to generate between 2 and 5 watts
of energy as the wearer walks--enough to
charge a cell phone or other small electronic
device.
The researchers anticipate that this will be
welcome news to outdoor enthusiasts, field
engineers, military personnel and emergency
responders who work in remote areas.
As far as Wang and his colleagues are concerned
however, human motion is only one potential
source for clean and renewable energy. In 2013,
the team demonstrated that it was possible to
use TENGs to extract energy from ocean waves.
The research report, "Harvesting Energy from
the Natural Vibration of Human Walking
", was published in the journal ACS Nano on
November 1, 2013
recharge wireless gadgets
New device harnesses the energy created by
natural human walking.
Credit and Larger Version
July 1, 2014
Editor's Note: This Behind the Scenes article was
first provided to LiveScience in partnership with
the National Science Foundation.
By the end of 2014, Earth will be home to more
mobile electronic devices than people .
Smartphones, tablets, e-readers, not to mention
wearable health and fitness trackers, smart
glasses and navigation devices--today's
population is more plugged in than ever before.
But our reliance on devices is not problem-free:
1. Wireless gadgets require regular recharging.
While we may think we've cut the cord, we
remain reliant on outlets and charging
stations to keep our devices up and
running.
2. According to a 2009 report by the
International Energy Agency (IEA),
consumer electronics and information and
communication technologies currently
account for nearly 15 percent of global
residential electricity consumption. What's
more, the IEA expects energy consumptions
by these devices to double by 2022 and to
triple by 2030--thereby slowly but surely
adding to the burden on our power
infrastructure.
With support from the National Science
Foundation, a team of researchers at the
Georgia Institute of Technology may have a
solution to both problems: They're developing a
new, portable, clean energy source that could
change the way we power mobile electronics:
human motion.
Led by material scientist Zhong Lin Wang, the
team has created a backpack that captures
mechanical energy from the natural vibration of
human walking and converts it into electrical
energy. This technology could revolutionize the
way we charge small electronic devices, and
thereby reduce the burden of these devices on
non-renewable power sources and untether
users from fixed charging stations.
Smaller, lighter, more energy efficient
Wearable generators that convert energy from
the body's mechanical potential into electricity
are not new, but traditional technologies rely on
bulky or fragile materials. By contrast, Wang's
backpack contains a device made from thin,
lightweight plastic sheets, interlocked in a
rhombic grid. (Think of the collapsible cardboard
containers that separate a six pack of fancy soda
bottles.)
As the wearer walks, the rhythmic movement
that occurs as his/her weight shifts from side to
side causes the inside surfaces of the plastic
sheets to touch and then separate, touch and
then separate. The periodic contact and
separation drives electrons back and forth,
producing an alternating electric current. This
process, known as the triboelectrification effect,
also underlies static electricity, a phenomenon
familiar to anyone who has ever pulled a freshly
laundered fleece jacket over his or her head in
January.
But the key to Wang's technology is the addition
of highly charged nanomaterials that maximize
the contact between the two surfaces, pumping
up the energy output of what Wang calls the
triboelectric nanogenerator (TENG).
"The TENG is as efficient as the best
electromagnetic generator, and is lighter and
smaller than any other electric generators for
mechanical energy conversion," says Wang. "The
efficiency will only improve with the invention of
new advanced materials."
Charging on the go
In the laboratory, Wang's team showed that
natural human walking with a load of 2
kilograms, about the weight of a 2-liter bottle of
soda, generated enough power to
simultaneously light more than 40 commercial
LEDs (which are the most efficient lights
available).
Wang says that the maximum power output
depends on the density of the surface
electrostatic charge, but that the backpack will
likely be able to generate between 2 and 5 watts
of energy as the wearer walks--enough to
charge a cell phone or other small electronic
device.
The researchers anticipate that this will be
welcome news to outdoor enthusiasts, field
engineers, military personnel and emergency
responders who work in remote areas.
As far as Wang and his colleagues are concerned
however, human motion is only one potential
source for clean and renewable energy. In 2013,
the team demonstrated that it was possible to
use TENGs to extract energy from ocean waves.
The research report, "Harvesting Energy from
the Natural Vibration of Human Walking
", was published in the journal ACS Nano on
November 1, 2013
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