Analysis of Dielectrophoretic Force by Using COMSOL

Department of Biomedical Engineering,Yonsei Universityy

Taewoo Lee

COMSOL CONFERENCE SEOUL 2013

Prof. Han-Sung KimCompuater Aided Biomedical Engineering Lab.p g ghttp://cabe.yonsei.ac.kr

Prof. Sang Woo LeeNano Bio System Research LabNano Bio System Research Lab.http://nbsrl.yonsei.ac.kr

Dielectrophoresis is a phenomenon in which a force is exerted on a dielectric particle when it is subjected to a non-uniform electric fielddielectric particle when it is subjected to a non-uniform electric field.

OutputSide view

p

Ground

Cover glass Silicon rubber

Glass substrate Electrode Medium (Cells or Beads)

Cover glass Silicon rubber

Top view

Cells or BeadsCells or Beads

Side view

Top view

SiO2 insulator Opening window

Unit model for simulation

45μmElectrode without SiO2

(Opening window)

13μm

zx

y

Gap betweenthe electrodes

0μm

5μm

yxElectrode with SiO2-8μm

0μm-5μm 10μm

Governing equations

• Dielectrophoretic (DEP) forcep

• Elecrohydrodynamic force

- Electrothermal force

• Gravitational & buoyant forcey

COMSOL Multiphysics 3.5a

MEMS

ModuleElectrostatics Electrostatics

COMSOL

MultiphysicsHeat Transfer

Convection and

Conduction

MEMSMEMS

ModuleMicrofluidics

Incompressible

Navier-Stokes

Results

• Slice: Temperature

• Arrow: Total heat flux

• Streamline: Velocity field

Result – Positive DEP

l b h h l d• Equilibrium height: Particle radius

N1.47e-19

N2.87e-9

1e-19

1e-20

1e-10

1e-11

1e-21

1e-22

1e-12

1e-13

1.78e-23

z

5.92e-15

Equilibrium heighty

DEP force EHD force

Equilibrium height

Result – Positive DEP

N

3.6e-10

N5.37e-10

y

2.7e-10

1.8e-10

Trapped position x

y

0.9e-10

7.26e-12

Result – Negative DEP

l b h h f• Equilibrium height: Net force = 0

N1.34e-9

N6.17e-14

1e-9

1e-10

1e-14

1e-15

1e-11

1e-12

1e-16

1e-17

z

2.11e-15 8.11e-18

y

DEP force EHD force

Result – Negative DEP

l b h h f• Equilibrium height: Net force = 0

DE

xy

Cxy

Result – Negative DEP

9.6e-15

N1.26e-14

7.2e-15

4.8e-15

2 4e-15

xy

2.4e-15

4.67e-16

Dotted line ATrapped position

Simulation vs. Experiment

Positive DEP

Negative DEPNegative DEP

5μm polystyrene beads

CM factor (Cells vs. Beads)

CM factor

Cells

Beads

CM factor

Frequency

DEP traps for single cell (B16F10)

Positive DEP force (3Vpp, 100kHz)Negative DEP force (3Vpp, 1kHz)

Positive DEP Trap in various window shapes

Rh b S HRhombus Square Hexagon

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