CMOS Single Chip Gas Detection Systems — Part I

Abstract

The current trend to control indoor air-quality and to monitor environmental pollution has created a strong demand for miniaturized and inexpensive gas sensors for volatile organic compounds (VOCs). Gas sensor arrays based on industrial CMOS-processes combined with post-CMOS micromachining (CMOS MEMS) are a promising approach to low-cost sensor devices. In this article, the state of research of CMOS-based gas sensor systems is reviewed, and a platform technology is described, which provides the possibility of monolithically integrating several different transducers on a single chip. A design environment, batch-fabrication processes, and fast testing procedures were developed to realize an example single-chip gas detection system. The chip includes the transducers, their biasing circuitry, reference elements, a digital interface, and a temperature sensor. The three polymer-based transducers and their interface electronics will be detailed in the second part of this article [1].

Integration of Chemical Sensors with LSI Technology — History and Applications —

“…It means to fabricate an array of integrated sensors arrays. Hagleitner et al developed a handheld gas sensing instrument for complex detection tasks [35]. It includes six singlechip multisensor systems assembled on a ceramic board and coated with different polymers, a microcontroller board (signal processing unit), a miniaturized gas-flow system, and a battery supplier.…”

CMOS Single‐chip Gas Detection Systems: Part II

“…The mechanical stability of the membranes and the maximum allowable chip-area determine the size limits. The membranes have sizes of 650 × 650 lm 2 (square membrane, see Figure 1.2.1) and 2150 × 750 lm 2 (rectangular membrane on the chip developed for glob-top packaging [1]), respectively.…”

“…The different miniaturized devices to assess the mass change of a sensitive layer (mostly polymeric) upon analyte absorption from the gas-phase have been discussed [1]. The operation principle of the resonant cantilever which is used for the multisensor chip is shown in Figure 1.2.42.…”

“…In the first part of this article [1], the state of research on CMOS-based gas sensor systems was reviewed, and a platform technology for monolithic integration of three different transducers on a single chip was described. In this second part, the transduction principles of three polymer-based gas sensors are detailed and the read-out circuitry is portrayed.…”

“…with the aim of reducing costs, size and time to market of array-based gas detection systems is discussed. The first part was published in a previous volume of this series [1], and included current research on CMOSbased gas sensors and the design, fabrication, and system aspects of a single-chip gas detection system. Figure 1.2.1 shows a micrograph of this multisensor chip, which comprises three transducers that respond to fundamentally different analyte properties.…”