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Antigravity pump lifts water upwards with no power source
- 21:00 11 June 2015 by Jacob Aron
Video: Antigravity pump
Carrying liquids up a hill usually involves a pump, or
a lot of buckets. But now it seems water can do some of the heavy
lifting itself.
Kesong Liu of Beihang University in
Beijing, China, and his colleagues have developed a way to lift water
with no need for an external source of energy. Although the technique
only works over short distances at the moment, it could be useful for microfluidic lab-on-a-chip devices that shift small amounts of water around to analyse diseases.
Key to the technique is a copper mesh
treated with an alkali solution to create microscopic pockets on its
surface, making it water-repellent, or superhydrophobic. The team placed
this mesh at the bottom of a vertical plastic pipe with a right-angle
joint at the top, which was filled with a small amount of water.
The superhydrophobic mesh repels the water
and stops it from falling, but doesn't transport it upwards. That
happens when a small droplet of water is placed underneath the mesh and
gets drawn into the column above, causing the top of the column to rise
slightly. Once enough water has been lifted to fill the pipe, it spills
out the other end (see video).
It may seem like magic, but it's all thanks to the surface tension of water.
When the droplet touches the larger column of water, this surface
tension breaks and the energy used to keep the droplet spherical goes
into lifting the water. "We thought, why not use water's own energy to
propel the antigravity delivery?" says Liu.
The antigravity device can only lift a
water column about 1 centimetre tall at most – beyond that, gravity
begins to win out over the water's own energy. But Liu thinks this could
still prove useful. "We believe that the current finding and design
should offer great opportunity to develop advanced microfluidic
devices," he says.
Journal reference: Advanced Functional Materials, DOI: 10.1002/adfm.201501320
end quote from:
http://www.newscientist.com/article/dn27710-antigravity-pump-lifts-water-upwards-with-no-power-source.html?cmpid=RSS|NSN
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