Biomedical Engineering Reference
In-Depth Information
Figure 6.65
Sketch of a deterministic array. Small particles stay in their own stream channel,
whereas large particles are forced to shift to the next stream channel at the approach of a post.
Let us analyze the situation into more details. In the schematic Figure 6.66,
rows of posts have been placed with a shift
e
at each level (here the shift
e
= 1/3).
The flow can be decomposed in
n
= 1/
b
streamlines (here
n
= 3, and the stream-
lines are noted as 1, 2, 3) having the same flow rate, equal to
e
times the flow rate
between two pillars. Consider a small spherical particle in the stream channel 1.
Always using the assumption that a particle or a cell follows the streamline passing
by its centroid, because the diameter of the particle
D
is less than 2
b
, the particle is
transported in its initial stream channel and globally has a straight trajectory. On
the other hand, a particle of diameter
D
> 2
b
cannot stay in channel 1 when passing
Figure 6.66
Schematic of a DLD device with
e
= 1/3.
