Scientists created a "tiny wind turbine" capable of scavenging energy from the tacit breeze we feel while swinging our arms in a walk, according to a recent study published in the journal Cell Reports Physical Science.
'Tiny wind turbine' collects energy from walker's swinging arms
The new wearable electric generator harvests energy from the wind generated during a simple walk, is low-cost, and efficient enough to power small LEDs and sensors, say scientists, The Guardian reports.
While it works with wind, the device isn't actually a wind turbine. Instead of spinning, it gathers energy via a mechanism not unlike what creates static electricity — called the triboelectric effect.
This phenomenon happens when material is electrically charged after separation from another material, and in this case the active component of the device consists of two plastic strips contained in a tube.
New device has 3.23% efficiency, best speeds for energy
When air flows through the tube, both strips flap and sporadically clap together — gathering and storing precious energy. The team of researchers from the Chinese Academy of Sciences claims the nanogenerator functions in winds as gentle as 3.6 mph (5.8 km/h), and showed promising results when attached to a walking person's arm.
However, it works best between speeds of 8.9 and 17.9 mph (14.3 and 28.8 km/h) — so it might be better suited for a bike ride.
The researchers also claimed the device has a wind-to-energy conversion efficiency of 3.23% — higher than comparable energy-scavenging devices, but still far below more dedicated wind energy gatherers. For example, traditional wind turbines have an efficiency of roughly 50%.
'Tiny wind turbine' device may be scaled up to 1,000 W
The new nanogenerator would probably be best suited for smaller devices. The fully-optimized version can maintain an output voltage of 175 V, a 43-μA current, and a power of 2.5 mW -- enough to supply power for an array of 100 LEDs, or small temperature sensors, New Atlas reports.
The novel design might eventually inspire newer kinds of wearable nanogenerators capable of powering small electronic devices. Some concepts include fabrics that gather energy from friction, while others tap sunlight and movement at the same time. There are even metallic tabs designed to gather energy from bending fingers.
"I'm hoping to scale up the device to produce 1,000 watts, so it's competitive with traditional wind turbines," said senior author of the study Ya Yang, reports New Atlas. "We can place these devices where traditional wind turbines can't reach. We can put it in the mountains or on top of buildings for sustainable energy."
Sustainable energy is the future, but the pathway there isn't always clear. Most interested parties agree fossil fuel is on its way out of the electrical infrastructure, but while there is division on whether solar, wind or even nuclear power is the best way forward — there will be no shortage of new portable inventions to explore, building on the engineering merits of new devices like this "tiny wind turbine."