1. 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

2. Outline Motivation Introduction Working Theory of DEP/twDEP Fabrication Experiment Results

3. 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 DIELECTROPHORESIS ) －＞ But after Reading ， … @#&%*! Ref: http://www.imm-mainz.de/upload/bilder/d137027ad17056118590d74d1c2b8b30.orig.jpg

4. Introduction DEP － conventional DEP (cDEP) 、 rotation DEP (rotDEP) 、 traveling-wave DEP (twDEP) 10MHz

5. Theory － DEP/twDEP DEP force － factor ： non-uniform electric field 、 electrical properties of particles & medium Ref: http://www.ibmm.informatics.bangor.ac.uk

6. 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

7. Clausius-Mossotti factor ( induced dipole moment factor)

8. Clausius-Mossotti factor Amplitude & Phase plot of

9. 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

10. Fabrication Electrode (Cr) Micro-channel (PDMS) Bonding (O 2 plasma) Ref: http://www.ndl.org.tw/old/ndlcomm/P12_1/3.pdf

11. Experiment Results (1) motion of whole blood cells being pumped by twDEP with phasing between electrodes

12. Experiment Results (2) Effect of electrode gap and voltage on average cell velocity F drag α Velocity F DEP α (Voltage)*2

13. Experiment Results (3) Bi-directional manipulation Fig. Computational result of twDEP force vectors

14. THE END Thanks for Your Attention!