1. 52300 Sensing and Actuation in Miniaturized Systems Professor ： Cheng-Hsien Liu Students ： Den-Hua Lee Topics ： Trap DNA/RNA in Microfluidic 2008/11/111

2. Outline The goal Introduction Experiments Results and discussion Conlusion 2008/11/112

3. The goal 2008/11/113

4. What happened in nearing the narrowest part of taper shape microfluidic channel The accumulation of flowing DNA Observed near the narrowest part of taper shape microfluidic channel Both hydro pressure and electric field are applied in the opposite direction The position and the shape of the accumulated DNA are changed with increasing the electric force and decreasing the hydro pressure 2008/11/114

5. Shape and size of narrowest part of taper shape channel for DNA/RNA trap. 2008/11/115 Reference 1

6. Three forces act on DNA dc dielectric force hydro drag force Lorentz force 2008/11/116

7. Using this technique The DNA, RNA, Protein, organelles can be trapped, concentrated, and extracted in mixed solution 2008/11/117

8. Introduction 2008/11/118

9. Experimental set up 2008/11/119 Reference 2

10. Structure of the taper shape microchannel 2008/11/1110 bovine serum albumin (BSA) Reference 2

11. Fluorescence image of nuclei trapping 2008/11/1111 Reference 2

12. Trapping condition of organelles 2008/11/1112 Reference 2

13. Fluorescence image of protein trapping 2008/11/1113 Reference 2

14. Experiments 2008/11/1114

15. The micro channel Was made of polydimethylsiloxane (PDMS) Long ： 30 mm Wide ： 100μm Deep ： 10μm At the center of the channel, a narrow part of 10μm wide 2008/11/1115

16. The micro channel 2008/11/1116 Reference 1

17. Typical photograph of trap DNA It shows mode transition with increasing applied voltage. 2008/11/1117 Reference 1

18. Condition map for each trap pattern The trap pattern is approximately depend on the ratio of pressure and voltage The same ratio shows the same pattern 2008/11/1118 Reference 1

19. Numerical simulation of the total force act on each DNA molecule Gray area shows the position where the hydro drag force and electric force is nearly balanced Using the COMSOL Multiphysics software 2008/11/1119 Reference 1

20. Results and Discussion 2008/11/1120

21. The results of three force acted The three force ： dc dielectric force, hydro drag force, Lorentz force. The result ： the DEP force is 10 -4 times smaller than the other Lorentz force and hydro drag force The condition for the mode transition was investigated at various pressure and voltage 2008/11/1121

22. Actual motion of the trapped DNA The dynamic motion of trap molecule around the balanced position of the two forces, dc electric force and hydro drag force The trap position ： located near the area where the two forces are balanced The balanced position ： move as changing the ratio of the two forces 2008/11/1122

23. Conclusion The position and shape of trapped DNA by hydro drag force and electric force in taper shape channel was investigated at various condition The position and the shape changed as a function of the ratio of the electric force and the hydro drag force The dielectric force is 10 -4 times smaller than the other forces, and hydro drag force and Lorentz force were major forces in this trap. 2008/11/1123

24. Reference 1 、 Yuzuru Takamura1, Wako Nagasaka1, Kunimitsu Ueno1,Yuichi Tomizawa1, and Eiichi Tamiya1,2 “ MODE TRANSITION & ITS MECHANISM OF RNA/DNA TRAP BY ELECTRIC AND HYDRAULIC FORCE FIELD IN MICROFLUIDIC TAPER SHAPE CHANNEL” uTAS proceeding, p1429-1431 (2007) 2 、 Yuichi Tomizawa, Hiroaki Oose, Kunimitsu Ueno, Md Shameen Ahsans, Naoki Nagatani, Wako Nagasaka, Eiichi Tamiya, and Yuzuru Takamura, “BIOMOLECULE AND ORGANELLE TRAP USING ELECTRIC AND HYDRODRAG FORCE FIELDS IN TAPER SHAPED MICROCHANNEL”, uTAS proceeding,, p900-902 (2006) 3 、 Carlos Bustamante, Steven B Smith, Jan Liphardt, Doug Smith, “Single- molecule studies of DNA mechanics”, Structural Biology 2000, 10:p279–285 2008/11/1124

25. Thank you