MANIPULATION OF WHOLE BLOOD USING TRAVELING WAVE DIELECTROPHORESIS

Y.J. Lo, A.M. Wo, and U. Lei

Institute of Applied Mechanics, National Taiwan University, Taipei, Taiwan

(MEMS2005 P.686~689)

Reporter: Chung-Kuang Chin( 秦重光 )

Date:10/24/2007

Outline

Motivation Introduction Working Theory of DEP/twDEP Fabrication Experiment Results

Motivation

Beautiful Life, Money －＞ Health Care －＞ Bio-Medical Science + MEMS －＞ Bio-MEMS ( “Lab on a Chip” ，” Micro-total analysis system” ) －＞ cell manipulation (μm) －＞ DEP force (working on whole blood is rare) －＞ This paper !!!! (MANIPULATION OF WHOLE BLOOD USING TRAVELING WAVE DIEL

ECTROPHORESIS ) －＞ But after Reading ，… @#&%*!

Ref: http://www.imm-mainz.de/upload/bilder/d137027ad17056118590d74d1c2b8b30.orig.jpg

Introduction

DEP － conventional DEP (cDEP) 、 rotation DEP (rotDEP) 、 traveling-wave DEP (twDEP)

10MHz

Theory － DEP/twDEP DEP force － factor ： non-uniform electric field 、 electrical properties of particles & m

edium

Ref: http://www.ibmm.informatics.bangor.ac.uk

Theory Formula

DEP force

( ， Clausius–Mossotti factor

ε ： permittivity ， ， σ ： conductivity ， ω ： angular frequency ， r ： particle radius

： rms value of the electric field strength ，

， (i=x,y,z) ： magnitude ， phase ) Real part －＞ (Conventional) DEP ， Imaginary part －＞ twDEP

3 * 2 * 2 2 22 Re Imm rms x x y y z zF t r K E K E E E

**

**

*

2 mp

mpK

ppp j*

mmm j*

rmsE

iE i

Clausius-Mossotti factor ( induced dipole moment factor)

**

**

*

2 mp

mpK

Clausius-Mossotti factor

Amplitude & Phase plot of *K

Particle Manipulation using DEP & twDEP

Figure When a particle is suspended in an alternating electric field which contains either a magnitude or phase gradient, a force is induced on the particle which acts either in the direction of the gradient or opposes it, according to whether or not the particle is more or less Polari able than the medium in which it is suspended.

Here, a particle experiences force due to (a) a non-uniform electric field (magnitude gradient); (b) a traveling electric field (phase gradient

Fabrication

Electrode (Cr) Micro-channel (PDMS) Bonding (O2 plasma)

Ref: http://www.ndl.org.tw/old/ndlcomm/P12_1/3.pdf

Experiment Results (1)

motion of whole blood cells being pumped by twDEP with phasing between electrodes

Experiment Results (2)

Effect of electrode gap and voltage on average cell velocity

Fdrag α Velocity FDEP α (Voltage)*2

Experiment Results (3)

Bi-directional manipulation

Fig. Computational result of twDEP force vectors

THE END

Thanks for Your Attention!