Fast temperature programmed sensing for micro-hotplate gas sensors

Author

Cavicchi, R.E. ; Suehle, J.S. ; Kreider, K.G. ; Gaitan, M. ; Chaparala, P.

Author_Institution

Chem. Sci. & Technol. Lab., Nat. Inst. of Stand. & Technol., Gaithersburg, MD, USA

Volume

16

Issue

6

fYear

1995

fDate

6/1/1995 12:00:00 AM

Firstpage

286

Lastpage

288

Abstract

We describe an operating mode of a gas sensor that greatly enhances the capability of the device to determine the composition of a sensed gas. The device consists of a micromachined hotplate with integrated heater, heat distribution plate, electrical contact pads, and sensing film. The temperature programmed sensing (TPS) technique uses millisecond timescale temperature changes to modify the rates for adsorption, desorption, and reaction of gases on the sensing surface during sensor operation. A repetitive train of temperature pulses produces a patterned conductance response that depends on the gas composition, as well as the temperature pulse width, amplitude, and specific sequence of pulses. Results are shown for the vapors of water, ethanol, methanol, formaldehyde, and acetone.

Keywords

gas sensors; adsorption; desorption; electrical contact pads; gas composition; heat distribution plate; micro-hotplate gas sensors; micromachined hotplate; millisecond timescale temperature changes; operating mode; patterned conductance response; semiconductor sensors; sensing surface; temperature programmed sensing; temperature pulse width; Conductive films; Ethanol; Gas detectors; Humidity; Methanol; Resistance heating; Sensor arrays; Space vector pulse width modulation; Temperature dependence; Temperature sensors;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/55.790737

Filename

790737