A miniature electronic nose system based on an MWNT-polymer microsensor array and a low-power signal-processing chip.

Area of Science:

• * Sensor Technology
• * Microelectronic Systems

Background:

• * Development of compact and energy-efficient sensing devices is crucial for portable applications.
• * Existing electronic nose (e-nose) systems often face challenges with power consumption and miniaturization.

Purpose of the Study:

• * To introduce a novel, power-efficient, and miniature electronic nose (e-nose) system.
• * To detail the design and fabrication of a microsensor array and a low-power signal-processing chip for the e-nose.

Main Methods:

• * Fabrication of a multiple-walled carbon nanotube (MWNT)-polymer microsensor array using photolithography and a two-layer deposition method.
• * Design and fabrication of a low-power signal-processing chip with data acquisition circuits and a microprocessor using a 0.18-μm CMOS process.
• * Integration of the microsensor array and signal-processing chip with a k-nearest-neighbor algorithm for odor classification.

Main Results:

• * The microsensor array featured eight interdigitated electrodes within a 650 × 760 μm area, utilizing SU-8 walls to confine materials.
• * The low-power signal-processing chip achieved a power consumption of 1.05 mW at specified supply voltages.
• * The prototype e-nose system demonstrated successful recognition of complex odors, including tincture, sorghum wine, sake, whisky, and vodka.

Conclusions:

• * The developed miniature e-nose system offers a power-efficient solution for odor detection.
• * The integration of the MWNT-polymer microsensor array and low-power chip enables effective odor classification.
• * This technology holds potential for various applications requiring portable and sensitive odor analysis.