The clip shows the time-dependence of the fluid velocity field, acquired by performing
time-resolved particle image velocimetry (PIV) on the yellow 1-μm beads in the clip
“Flow-free transport and caging of 5-μm beads”. Note that at 5-second intervals, e.g. around 12 and 17
seconds, the fluid velocity increases in the cage due to rapid movement of the caged
aggregate as the frequency jumps back to its lowest value. Additionally, the rapid
transport of aggregates in the inlet channel is also apparent at these times, with a leftward
flow in front of and behind the aggregate and a rightward flow over its sides, as it pushes
through the fluid. The velocity field has been numerically smoothed. The average
velocity field during the full clip is shown in Fig. 4c.
In the first, second and third clips, the chip was actuated by two transducers; one driven
in linear sweeps from 2.60 2.64 MHz at a rate of 0.5 Hz (first clip) or 0.2 Hz (second
and third clips), and the other driven from 6.90 7.00 MHz at a rate of 1 kHz.

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Read the article at http://xlink.rsc.org/?DOI=b806946h

Duration : 0:0:10