Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-29T11:10:12.139Z Has data issue: false hasContentIssue false
  • English
  • Français

Relative Resistance Chemical Sensors Built on Microhotplate Platforms

Published online by Cambridge University Press:  01 February 2011

Joshua L. Hertz ,
Christopher B. Montgomery ,
David L. Lahr  and
Steve Semancik
Joshua L. Hertz
Affiliation:
joshua.hertz@nist.gov, National Institute of Standards and Technology, Chemical Science and Technology Laboratory, 100 Bureau Dr., MS 8362, Gaithersburg, MD, 20899, United States, 301-975-2615
Christopher B. Montgomery
Affiliation:
christopher.montgomery@nist.gov, National Institute of Standards and Technology, Chemical Science and Technology Laboratory, 100 Bureau Dr., MS 8362, Gaithersburg, MD, 20899, United States
David L. Lahr
Affiliation:
david.lahr@nist.gov, National Institute of Standards and Technology, Chemical Science and Technology Laboratory, 100 Bureau Dr., MS 8362, Gaithersburg, MD, 20899, United States
Steve Semancik
Affiliation:
stephen.semancik@nist.gov, National Institute of Standards and Technology, Chemical Science and Technology Laboratory, 100 Bureau Dr., MS 8362, Gaithersburg, MD, 20899, United States
Get access

Abstract

The selectivity, sensitivity, and speed of metal oxide conductometric chemical sensors can be improved by integrating them onto micromachined, thermally-controlled platforms (i.e., microhotplates). The improvements largely arise from the richness of signal inherent in arrays of multiple sensing materials and the ability to rapidly pulse and collect data at multiple temperatures. Unfortunately, like their macroscopic counterparts, these sensors can suffer from a lack of repeatability from sample-to-sample and even run-to-run. Here we report on a method to reduce signal drift and increase repeatability that is easily integrated with microhotplate chemical sensors. The method involves passivating one of a pair of identically-formed sensors by coating it with a highly electrically resistive and chemically impermeable film. Relative resistance measurements between the active and passive members of a pair then provide a signal that is reasonably constant over time despite electrical, thermal and gas flow rate fluctuations. Common modes of signal drift, such as microstructural changes within the sensing film, are also removed. The method is demonstrated using SnO2 and TiO2 microhotplate gas sensors, with a thin Al2O3 film forming the passivation layer. It is shown that methanol and acetone at concentrations of 1 µmol/mol, and possibly lower, are sensed with high reproducibility.

Keywords

sensoroxidepassivation
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 1052: Symposium DD – Microelectromechanical Systems–Materials and Devices , 2007 , 1052-DD05-03
Copyright
Copyright © Materials Research Society 2008

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1 Cavicchi, R.E., Suehle, J.S., Kreider, K.G., Shomaker, B.L., Small, J.A., Gaitan, M. and Chaparala, P., Appl. Phys. Lett. 66, 812 (1995).Google Scholar
2 Semancik, S. and Cavicchi, R., Acc. Chem. Res. 31, 279 (1998).Google Scholar
3 Kunt, T.A., McAvoy, T.J., Cavicchi, R.E. and Semancik, S., Sens. Actuators B 53, 24 (1998).Google Scholar
4 Artursson, T., Eklöv, T., Lundström, I., Mårtensson, P., Sjöström, M. and Holmberg, M., J. Chemom. 14, 711 (2000).Google Scholar
5 Holmin, S., Krantz-Rülcker, C., Lundström, I. and Winquist, F., Meas. Sci. Technol. 12, 1348 (2001).Google Scholar
6 Tomic, O., Ulmer, H. and Haugen, J.-E., Anal. Chim. Acta 472, 99 (2002).Google Scholar
7 Hui, D., Jun-hua, L. and Zhong-ru, S., Sens. Actuators B 96, 354 (2003).Google Scholar
8 Paniagua, M., Llobet, E., Brezmes, J., Vilanova, X., Correig, X. and Hines, E.L., Electron. Lett. 39, 40 (2003).Google Scholar
9 Zuppa, M., Distante, C., Siciliano, P. and Persaud, K.C., Sens. Actuators B 98, 305 (2004).Google Scholar
10 Sisk, B.C. and Lewis, N.S., Sens. Actuators B 104, 249 (2005).Google Scholar