1. Holly Tourtillott University of Missouri
Characterization of Carbon Nanofibers/Cavities and Microelectrode Fabrication for Biosensors Application
Holly Tourtillott
University of Missouri
Faculty Advisor: Dr. Uche Wejinya
Graduate Student Advisor: Zhuxin Dong
Department of Mechanical Engineering, University of Arkansas
July 20, 2009
Micro and Nano Systems Engineering Laboratory, University of Arkansas

2. Micro and Nano Systems Engineering Laboratory, University of Arkansas
Outline
Carbon Nanotubes
Microelectrode Fabrication
Characterization of Carbon Nanofibers on Electrodes
Experiment and Results
Conclusion and Future Work
References
Micro and Nano Systems Engineering Laboratory, University of Arkansas

3. Micro and Nano Systems Engineering Laboratory, University of Arkansas
Carbon Nanotubes
Carbon nanotubes have remarkable electrical, mechanical and thermal properties.
This research focuses on carbon nanotubes band structure to ultimately identify their electrical properties.
Using the Atomic Force Microscope and dielectrophoresis, the band structure and therefore conductivity of the CNTs can be determined.
The DEP process is used to align and determine the characteristics of the nanofibers.
Micro and Nano Systems Engineering Laboratory, University of Arkansas

4. Microelectrode Fabrication
The DEP process requires the fabrication of a microelectrode chip.
Micro and Nano Systems Engineering Laboratory, University of Arkansas

5. Microelectrode Fabrication
The DEP process requires the fabrication of a microelectrode chip.
Micro and Nano Systems Engineering Laboratory, University of Arkansas

6. Characterization of Carbon Nanofibers on Microelectrodes
Using an Agilent 5500-ILM Atomic Force Microscope (AFM), scanning of a microelectrode chip may be conducted.
The AFM is a very high-resolution type of scanning probe microscope that has resolution of fractions of a nanometer. We can use this microscope to measure the z-direction of a nanoparticle and in our case the height of the microelectrode chip fibers.
Micro and Nano Systems Engineering Laboratory, University of Arkansas

7. Characterization of Carbon Nanofibers on Microelectrodes
Micro and Nano Systems Engineering Laboratory, University of Arkansas

8. Characterization of Carbon Nanofibers on Microelectrodes
200 μm square
A1 = Array 1
C1 = Contact Pad 1
Micro and Nano Systems Engineering Laboratory, University of Arkansas

9. Characterization of Carbon Nanofibers on Microelectrodes
A 9×9µm area scanned in one array, cavities and fibers are found.
Cavity
Fiber
9 arrays under camera view to scan
3D topography image
Micro and Nano Systems Engineering Laboratory, University of Arkansas

10. Experiment and Results
Micro and Nano Systems Engineering Laboratory, University of Arkansas

11. Conclusion and Future Work
Throughout this research, the fabrication of a microelectrode chip was completed as well as the scanning of two NASA microelectrode chips.
Future work includes the use of the completed microelectrode chip that was fabricated in this research. This chip was made specifically for the DEP process of aligning carbon nanotubes and ultimately further research in assisting the biosensor applications technology.
Micro and Nano Systems Engineering Laboratory, University of Arkansas

12. Micro and Nano Systems Engineering Laboratory, University of Arkansas
References
-Microscope: Agilent 5500 ILM, Atomic Force Microscope
-Website:
-Book: Carbon Nanotube- Multifunctional Material, Edited by Prakash R. Somani and M. Umeno, Applied Science Innovations
-Website:
Publication: Zhuxin Dong, Uchechukwu C. Wejinya, Haibo Yu, and Imad H. Elhajj. “Design, Fabrication and Testing of CNT Based ISFET for NANO pH Sensor Application: A Preliminary Study.”
Publication: Kunal Ghosh. “Electronic Band Structure of Carbon Nanotubes.”
Micro and Nano Systems Engineering Laboratory, University of Arkansas

13. Micro and Nano Systems Engineering Laboratory, University of Arkansas
Thank You!
Any Questions?
Micro and Nano Systems Engineering Laboratory, University of Arkansas