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Swimming Against the Flow

A revolutionary and rapid coronavirus detection device

nother coronavirus‫־‬related development is based on a Assoc. Prof. Bercovici:
"The main advantage
A study conducted by a collaboration of researchers from of this method is
that it requires a very
the Technion and the IBM Research labs in Switzerland. small amount of fluid
It is a revolutionary device that in the future can aid in the rapid to make a positive
diagnosis of coronavirus and other viruses in patients, using diagnosis. The average
throat swab samples. The research team was led by Assoc. Prof. volume of a teardrop
Moran Bercovici, Associate Professor at the faculty and Head of is several microliters;
the Microfluidic Technologies Laboratory. our device needs only
The new device separates particles from biogenic fluids based one-hundredth of a
on their size, through the application of an electric field, using teardrop to work."
a process dubbed BFF (Bidirectional Flow Filter). The fluid
simultaneously flows in opposite directions, enabling the device
to separate different types of particles: The larger particles move
away at a faster pace, while the smaller particles remain closer
to the filter’s point of entry. The smaller particles are in fact
moving rapidly, but they remain in place because they fluctuate
between the opposing flows and thus, their average speed is
zero. In other words, once the swab sample is put into the device,
the comparatively large viral particles (coronavirus and others),
whose diameter ranges around 100 nanometers, are separated
from the other, smaller particles such as antibodies, whose
average size is approximately 10 nanometers.
"Imagine that you are rafting down a very special river that flows
in two directions at once, like a two‫־‬way street," explains Assoc.
Prof. Bercovici. "Suppose you use your paddles to cross over
to the opposing flow, and then back to the first, and then over
again. Your net speed will be zero. Nanoparticles do this paddling
naturally, but larger particles are lazy, and they stay in their
original flow and float away down the river."
Assoc. Prof. Bercovici stresses that "the main advantage in this
method is that it requires a very small amount of fluid to make
a positive diagnosis. To give you a sense of scale, the average
volume of a teardrop is several microliters; our device needs only
one‫־‬hundredth of a teardrop. No other method available today is
able to isolate viruses from such small sample volumes without
losing much of the sample fluid itself."

14 | MEgazine | Faculty of Mechanical Engineering