1.  Lyon, France  June 12, 2007 | Christophe Yamahata  Electrical & Mechanical characteristics of DNA bundles revealed by Silicon Nanotweezers C. Yamahata, T. Takekawa, M. Kumemura, M. Hosogi, G. Hashiguchi, D. Collard & Hiroyuki Fujita  The University of Tokyo Institute of Industrial Science Kagawa University Faculty of Engineering

2.  Lyon, France  June 12, 2007 | Christophe Yamahata  Electrical & Mechanical characteristics of DNA bundles revealed by Silicon Nanotweezers  Scope of the research Working principle & Microfabrication of the Silicon Nanotweezers DNA trapping by dielectrophoresis Electrical & Mechanical characterization of DNA bundles Conclusion & Outlook     

3.  Lyon, France  June 12, 2007 | Christophe Yamahata  Scope of the research 

4.  Lyon, France  June 12, 2007 | Christophe Yamahata   Scope of the research Biophysical tools used for molecular manipulation Optical tweezers Magnetic tweezers AFM probes * D. Collard et al., IEEJ Trans 2: 262–271, 2007

5.  Lyon, France  June 12, 2007 | Christophe Yamahata   Scope of the research Biophysical tools used for molecular manipulation Optical tweezers Magnetic tweezers AFM probes * D. Collard et al., IEEJ Trans 2: 262–271, 2007

6.  Lyon, France  June 12, 2007 | Christophe Yamahata   Scope of the research Biophysical tools used for molecular manipulation Optical tweezers Magnetic tweezers AFM probes * D. Collard et al., IEEJ Trans 2: 262–271, 2007

7.  Lyon, France  June 12, 2007 | Christophe Yamahata   Scope of the research Biophysical tools used for molecular manipulation Optical tweezers Magnetic tweezers AFM probes and Silicon nanotweezers * D. Collard et al., IEEJ Trans 2: 262–271, 2007

8.  Lyon, France  June 12, 2007 | Christophe Yamahata  Working principle & Microfabrication of the Silicon Nanotweezers Working principle Microfabrication technology 

9.  Lyon, France  June 12, 2007 | Christophe Yamahata   Working principle of the Silicon Nanotweezers External dimensions: 4.5 mm × 5.5 mm SOI wafer  The different elements are: Electrically insulated Mechanically locked with each other

10.  Lyon, France  June 12, 2007 | Christophe Yamahata   Working principle of the Silicon Nanotweezers

11.  Lyon, France  June 12, 2007 | Christophe Yamahata   Working principle of the Silicon Nanotweezers Differential capacitive sensor

12.  Lyon, France  June 12, 2007 | Christophe Yamahata   Working principle of the Silicon Nanotweezers Differential capacitive sensor MS3110 Universal Capacitive Readout™ (Irvine sensors, CA, USA)

13.  Lyon, France  June 12, 2007 | Christophe Yamahata  Working principle & Microfabrication of the Silicon Nanotweezers Working principle Microfabrication technology 

14.  Lyon, France  June 12, 2007 | Christophe Yamahata  (1) Si 3 N 4 deposition (LPCVD) + patterning(2) Silicon etching (RIE)(3) SiO 2 oxidation (LOCOS) + Si 3 N 4 removal (4) KOH anisotropic etching of Silicon  facets  Microfabrication technology (5) HF removal of buried oxide Si Si 3 N 4 SiO 2 (6) Backside etching by deep-RIE (with Al mask) SOI wafer (100)-Si layer: 25 µm Oxide layer: 2 µm Handling wafer: 380 µm

15.  Lyon, France  June 12, 2007 | Christophe Yamahata  Microfabrication technology Si Si 3 N 4 SiO 2  (1) (2) (3) (4) (5) (6)  SOI wafer (100)-Si layer: 25 µm Oxide layer: 2 µm Handling wafer: 380 µm

16.  Lyon, France  June 12, 2007 | Christophe Yamahata  Microfabrication technology 

17.  Lyon, France  June 12, 2007 | Christophe Yamahata  DNA trapping by dielectrophoresis 

18.  Lyon, France  June 12, 2007 | Christophe Yamahata   DNA trapping by dielectrophoresis (DEP) Droplet: λ-DNA: 12 nmol/L DI water: 5 µL Dielectrophoresis (DEP): 30 sec @ 1 MHz, 40 V pp (20 µm gap)

19.  Lyon, France  June 12, 2007 | Christophe Yamahata  λ-DNA bundle 20 µm gap diameter ~ 380 nm  DNA trapping by dielectrophoresis (DEP)

20.  Lyon, France  June 12, 2007 | Christophe Yamahata   Electrical & Mechanical characterization of DNA bundles Electrical characterization Mechanical characterization 

21.  Lyon, France  June 12, 2007 | Christophe Yamahata  Humidity generator Ambient air Pump Gas washing bottle Mixer Temperature and humidity sensor Glove box Faraday cage Keithley 6487 Picoammeter / Voltage Source chassis desiccant saturator  Electrical characterization of DNA bundles Experimental setup

22.  Lyon, France  June 12, 2007 | Christophe Yamahata   Electrical characterization of DNA bundles ~ 20 GΩ ~ 5 TΩ Measurements for different DNA bundles diameters  Quasi-ohmic behavior Measurements on “wet” DNA bundles (various diameters) T = 25 °C rh ~ 55% humidity

23.  Lyon, France  June 12, 2007 | Christophe Yamahata  Measurements on “wet” DNA bundles (various diameters)  Conductivity  bundle section  Electrical characterization of DNA bundles Measurements for different DNA bundles diameters  Effect of DNA bundle diameter

24.  Lyon, France  June 12, 2007 | Christophe Yamahata   Electrical characterization of DNA bundles Effect of humidity  Exponential dependence with relative humidity Transient current recording for a 5V step. Data recorded at 21 °C (  1°C overall fluctuation) for different humidity levels (rh  0.2% for each curve)

25.  Lyon, France  June 12, 2007 | Christophe Yamahata   Electrical characterization of DNA bundles Effect of humidity  Exponential dependence with relative humidity Data extracted from previous measurements (5V step) after 60 sec. (rh was decreased from 75% to 45% in 6 hours)

26.  Lyon, France  June 12, 2007 | Christophe Yamahata   Electrical & Mechanical characterization of DNA bundles Electrical characterization Mechanical characterization 

27.  Lyon, France  June 12, 2007 | Christophe Yamahata   Mechanical characterization of DNA bundles Displacement: ~ 3 µm  C max  200 fF Sensitivity: 2 V/pF  150 mV/µm Error: ε <1 mV   5 nm resolution  Characterization of empty tweezers Measurements performed with the MS3110 Universal Capacitive Readout™

28.  Lyon, France  June 12, 2007 | Christophe Yamahata  Sensitivity of the capacitive sensor enables the measurement of few nN forces (single DNA  ~ 80 pN)  Bundle stretching can be observed  Mechanical characterization of DNA bundles  Measurements after DNA bundle trapping Measurements performed with the MS3110 Universal Capacitive Readout™

29.  Lyon, France  June 12, 2007 | Christophe Yamahata  Conclusion & Outlook 

30.  Lyon, France  June 12, 2007 | Christophe Yamahata   Conclusion & Outlook Efficient trapping of DNA by dielectrophoresis Extensive electrical characterization of DNA bundles Displacement: 2-3 µm range / few nm resolution Force: few nN sensitivity  High potential for biophysical characterization of long macromolecules. e.g.: DNA bundle, microtubules, actin filament, etc. A new type of biophysical tool has been proposed:

31.  Lyon, France  June 12, 2007 | Christophe Yamahata    Acknowledgments 

32.  Lyon, France  June 12, 2007 | Christophe Yamahata  Swiss National Science Foundation (SNSF) Japan Society for the Promotion of Science (JSPS) Japan Science and Technology Corporation (JST) Centre National de la Recherche Scientifique (CNRS) Acknowledgments 

33.  Lyon, France  June 12, 2007 | Christophe Yamahata  Thank you for your attention.