Cell-Based Chips for Biotechnology - Introduction to BioMEMS - page 256

Inner
inlet

Outer
inlet

a

Flow

Inner
outlet

Outer
outlet

F L - F D
F L + F D

F D
F D

1
2

3
4

Lift force Dean drag

b

Inner
wall

Outer
wall

c

De = 0.47

1.9 µm beads

7.3 µm beads

Inlet Outlet

FIGURE 5.12 Particle.separation.using.spiral.microchannels..(From.Ali.Asgar.S..Bhagat,.Sathyakumar.
S..Kuntaegowdanahalli,.and.Ian.Papautsky,.“Continuous.particle.separation.in.spiral.microchannels.
using.dean.lows.and.differential.migration,”. Lab Chip .8,.1906-1914,.2008..Adapted.with.permis-
sion.from.The.Royal.Society.of.Chemistry.)

Liquid with particles

Broadened
segment

Detection
line

a

Pinched
segment

b

Separation of six bead sizes

70
60
50
40
30
20
10
0 0

Liquid without
particles

0.5 1 1.5

Diameter of the beads [µm]

2 2.5 3 3.5 4

FIGURE 5.13 Pinched-low.fractionation.of.beads..(a,.from.Masumi.Yamada,.Megumi.Nakashima,.and.
Minoru.Seki,.“Pinched.low.fractionation:.Continuous.size.separation.of.particles.utilizing.a.laminar.low.
proile.in.a.pinched.microchannel,”. Anal. Chem. .76,.5465-5471,.2004..Reprinted.with.permission.from.
the.American.Chemical.Society;.b,.from.Asger.Vig.Larsen,.Lena.Poulsen,.Henrik.Birgens,.Martin.Dufva,.
and.Anders.Kristensen,.“Pinched.low.fractionation.devices.for.detection.of.single.nucleotide.polymor-
phisms,”. Lab Chip .8,.818-821,.2008..Reprinted.with.permission.from.The.Royal.Society of Chemistry.)