Film type solid polymer ionomer sensor and sensor cell

Abstract

A miniaturized gas sensor including film type electrodes, and a solid ionomer electrolyte, for the detection of toxic gases, i.e., carbon monoxide, and other oxidizable or reducible gases and vapors is described. The all-solid planar sensor cell has two or more film type electrodes arranged on a non-conductive planar surface of a supportive material. The electrodes are discrete and in intimate contact with the same solid polymer ionomer membrane. The sensor cell contains no liquid electrolyte and is operated in a potentiostatic or potentiodynamic mode. The unique feature of the sensor cell is that high sensitivity to a select gas or vapor is achieved by a novel three-phase contact area design for a sensing electrode which is easily accessible to the gas sample via small diffusion openings or holes that penetrate through the solid polymer ionomer membrane layer above the sensing electrode. A significant signal to background noise enhancement is achieved for these film type sensor cells by processes that increase the three-phase contact area.

Description

technical field [0001] The present invention relates to a gas sensor, and more particularly to a miniaturized gas sensor with film type electrodes and a solid ionomer electrolyte. Background technique [0002] Research on membrane-based technologies has been carried out for a wide variety of sensors, as reported by: Wenyi et al., 1997; hughes et al., 1997; Staley et al., 1996; Agbor et al., 1995; Tan and Tan, 1995; Menil et al., 1994; Kunnecke et al., 1994; Creasey and Vamey, 1994; Geistlinger, 1993; Ishiji et al., 1993; Najafi et al., 1992; Hampp et al., 1992; Nakano and Ogawa, 1994; and Miura, 1994. Although solid-state gas sensors have the advantage of being able to operate at high temperatures, they also suffer from slow response and recovery times and high internal operating temperatures, as reported by: Liu et al., 1993; Narducci et al., 1993; and more recently Schwebel et al., 1997; Sheng et al., 1997; and Micocci et al., 1997. Only after...

AI Technical Summary

Problems solved by technology

[0005] A disadvantage of the prior art sensors described above is that the signal-to-noise ratio may not be conducive to the detection of very low concentrations (parts per billion, ppb) of important environmental and biomedical gases and vapors

Additionally, response times may be slow and reproducibility between sensors and sensor units may be difficult to achieve

Sensors are also more expensive

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