Characterization of Carbon Nanofibers/Cavities and Microelectrode Fabrication for Biosensors Application

Holly TourtillottUniversity of Missouri

Faculty Advisor: Dr. Uche WejinyaGraduate Student Advisor: Zhuxin Dong

Department of Mechanical Engineering, University of Arkansas July 20, 2009

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

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

Microelectrode Fabrication

• The DEP process requires the fabrication of a microelectrode chip.

Micro and Nano Systems Engineering Laboratory, University of Arkansas

Microelectrode Fabrication

• The DEP process requires the fabrication of a microelectrode chip.

Micro and Nano Systems Engineering Laboratory, University of Arkansas

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

Characterization of Carbon Nanofibers on Microelectrodes

Micro and Nano Systems Engineering Laboratory, University of Arkansas

Characterization of Carbon Nanofibers on Microelectrodes

A1

A7

A6 A9

A2 A4 A8

A3 A5

A1 = Array 1 C1 = Contact Pad 1

C1 C9

C1 C9

C3C2 C4 C5 C6 C8C7

200 μm square

Micro and Nano Systems Engineering Laboratory, University of Arkansas

Characterization of Carbon Nanofibers on Microelectrodes

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9 arrays under camera view to scan

3D topography image

Micro and Nano Systems Engineering Laboratory, University of Arkansas

A 9×9µm area scanned in one array, cavities and fibers are found.

Cavity

Fiber

Experiment and Results

10Micro and Nano Systems Engineering Laboratory, University of Arkansas

Conclusion and Future Work

11Micro and Nano Systems Engineering Laboratory, University of Arkansas

• 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.

References

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-Microscope: Agilent 5500 ILM, Atomic Force Microscope-Website: http://en.wikipedia.org/wiki/Carbon_nanotubes-Book: Carbon Nanotube- Multifunctional Material, Edited by Prakash R. Somani and M. Umeno, Applied Science Innovations -Website: http://ieeeexplore.org/nanotubes- 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

13Micro and Nano Systems Engineering Laboratory, University of Arkansas