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Controlled Fabrication of Nanostructure Material Based Chemical Sensors

Published online by Cambridge University Press:  01 February 2011

Laura J Evans
Affiliation:
[email protected], NASA, Glenn Research Center, Cleveland, Ohio, United States
Gary W. Hunter
Affiliation:
[email protected], NASA, Glenn Research Center, Cleveland, Ohio, United States
Jennifer C. Xu
Affiliation:
[email protected], NASA, Glenn Research Center, Cleveland, Ohio, United States
Gordon M. Berger
Affiliation:
[email protected], USRA, Glenn Research Center, Cleveland, Ohio, United States
Randall L. Vander Wal
Affiliation:
[email protected], The Pennsylvania State University, Energy and Mineral Engineering, University Park, Pennsylvania, United States
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Abstract

The use of nanotechnology based materials for chemical sensing has been of great interest since nanocrystalline materials have been shown to offer improved sensor sensitivity, stability, and response time. Several groups are successfully integrating nanostructures such as nanowires into operational sensors. The typical procedure may include random placement (e.g., dispersion, with fine-line patterning techniques used to create functional sensors) or time consuming precise fabrication (e.g., mechanical placement using an atomic force microscope or laser tweezer techniques). Dielectrophoresis has also been utilized, however it can be challenging to achieve good electrical contact of the nanostructures to the underlying electrodes. In this paper we report on a sensor platform that incorporates nanorods in a controlled, efficient, and effective manner. Semiconducting SnO2 nanorods are used as the sensing element for detection of hydrogen (H2) and propylene (C3H6) up to 600oC. Using a novel approach of combining dielectrophoresis with standard microfabrication processing techniques, we have achieved reproducible, time-efficient fabrication of gas sensors with reliable contacts to the SnO2 nanorods used for the detection of gases. The sensor layout is designed to assist in the alignment of the nanorods by selectively enhancing the electric field strength and allowing for the quick production of sensor arrays. The SnO2 nanorods are produced using a thermal evaporation-condensation approach. After growth, nanorods are separated from the resulting material using gravimetric separation. The rods vary in length from 3μm to greater than 10μm, with diameters ranging from 50 to 300nm. Dielectrophoresis is used to align multiple nanorods between electrodes. A second layer of metal is incorporated using standard microfabrication methods immediately after alignment to bury the ends of the rods making contact with the underlying electrodes within another layer of metal. Electrical contact was verified during testing by the response to H2 and C3H6 gases at a range of temperatures. Testing was performed on a stage with temperature control and probes were used for electrical contact. Gas flows into the testing chamber at a flow rate of 4000sccm. Sensor response of normalized current shift, |Igas-Iair|/Iair, was measured at a constant voltage bias. Sensors showed response to both H2 and C3H6. Detection of H2 was achieved at 100oC and response levels improved approximately 12000-fold at 600oC. Detection of C3H6 started at 100oC and improved approximately 10000-fold at 600oC. Detection of at least 200ppm for both gases was achieved at 600oC. Using this novel microfabrication approach, semiconducting SnO2 nanorods integrated into a microsensor platform have been demonstrated and sensing response showed dramatic increases at higher temperatures.

Type
Research Article
Copyright
Copyright © Materials Research Society 2010

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References

1 Shen, G. Chen, P.C. Ryu, K. and Zhou, C. J. Mater. Chem., 19, 828839 (2009).Google Scholar
2 Cosandey, F. Skandan, G. and Singhal, A. JOM-e, 52 (10), (2000).Google Scholar
3 Huang, X.J. and Choi, Y.K. Sensors and Actuators B: Chemical, 122 (2), 659671 (2007).Google Scholar
4 Hunter, G.W. Vander Wal, R.L., Xu, J.C. Evans, L.J. Berger, G.M. and Kulis, M.J. ECS Trans., 16 (14), 7384 (2008).Google Scholar
5 Zimmler, M.A. Stichtenoth, D. Ronning, C. Yi, W. Narayanamurti, V. Voss, T. and Capasso, F., Nano Lett., 8 (6), 16951699 (2008).Google Scholar
6 McAlpine, M.C. Ahmad, H. Wang, D. and Heath, J.R. Nat. Mat 6 (5), 379384 (2007).Google Scholar
7 Hunter, G.W. R.L. Vander Wal, Evans, L.J. Xu, J.C. Berger, G.M. Kulis, M.J. Biaggi-Labiosa, A.M., J. Electrochem. Soc., (2010), submitted.Google Scholar
8 Wal, R.L. Vander, Berger, G.M. Kulis, M.J. Hunter, G.W. Xu, J.C. Evans, L.J. Sensors,9, 78667902 (2009).Google Scholar
9 Chang, D.E. and Petit, N. Int. J. Robust Nonlinear Control, 15, 769784 (2005).Google Scholar
10 Kumar, S. Peng, Z. Shin, H. Wang, Z.L. Hesketh, P.J. Anal. Chem., 82 (6), 22042212 (2010).Google Scholar
11 Evoy, S. DiLello, N. Deshpande, V. Narayanan, A. Liu, H. Riegelman, M. Martin, B.R. Hailer, B., Bradley, J.C. Weiss, W. Mayer, T.S. Gogotsi, Y. Bau, H.H. Mallouk, T.E. and Raman, S., Microelectronic Engineering, 75, 3142 (2004).Google Scholar
12 Microposit S1805 Photoresist, Shipley Company, Marlborough, MA.Google Scholar
13 Dweik, R.A. Comhair, S.A.A. Gaston, B. Thunnissen, F.B.J.M. Farver, C. Thomassen, M.J. Kavuru, M. Hammel, J. Abu-Soud, H.M., Erzurum, S.C. Proc. Natl. Acad. Sci. of the U.S.A., 98 (5), 26222627 (2001).Google Scholar
14 Silkoff, P.E. McClean, P. Spino, M. Erlich, L. Slutsky, A.S. Zamel, N. Chest, 119 (5), 13221328 (2001).Google Scholar
15 Dweik, R.A. Laskowski, D. Abu-Soud, H.M., Kaneko, F. Hutte, R. Stuehr, D.J. Erzurum, S.C., J. Clin. Invest. 101 (3), 660666 (1998).Google Scholar
16 Ward, B. presented at the 2008 12th Annual Test Instrumentation Workshop, Pensacola, FL.Google Scholar