A Three-Step Resolution-Reconfigurable Hazardous Multi-Gas Sensor Interface for Wireless Air-Quality Monitoring Applications

Subin Choi; Kyeonghwan Park; Seungwook Lee; Yeongjin Lim; Byungjoo Oh; Hee Young Chae; Chan Sam Park; Heugjoo Shin; Jae Joon Kim

doi:10.3390/s18030761

A Three-Step Resolution-Reconfigurable Hazardous Multi-Gas Sensor Interface for Wireless Air-Quality Monitoring Applications

Sensors (Basel). 2018 Mar 2;18(3):761. doi: 10.3390/s18030761.

Authors

Subin Choi¹, Kyeonghwan Park², Seungwook Lee³, Yeongjin Lim⁴, Byungjoo Oh⁵, Hee Young Chae⁶, Chan Sam Park⁷, Heugjoo Shin⁸, Jae Joon Kim⁹

Affiliations

¹ School of Electrical and Computer Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea. yj2821@unist.ac.kr.
² School of Electrical and Computer Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea. khpark@unist.ac.kr.
³ School of Mechanical, Aerospace and Nuclear Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea. zhffk9@unist.ac.kr.
⁴ School of Mechanical, Aerospace and Nuclear Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea. yjlim@unist.ac.kr.
⁵ School of Electrical and Computer Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea. ohbj87@unist.ac.kr.
⁶ School of Electrical and Computer Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea. laplume@unist.ac.kr.
⁷ School of Electrical and Computer Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea. chan4517@unist.ac.kr.
⁸ School of Mechanical, Aerospace and Nuclear Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea. hjshin@unist.ac.kr.
⁹ School of Electrical and Computer Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea. jaejoon@unist.ac.kr.

Abstract

This paper presents a resolution-reconfigurable wide-range resistive sensor readout interface for wireless multi-gas monitoring applications that displays results on a smartphone. Three types of sensing resolutions were selected to minimize processing power consumption, and a dual-mode front-end structure was proposed to support the detection of a variety of hazardous gases with wide range of characteristic resistance. The readout integrated circuit (ROIC) was fabricated in a 0.18 μm CMOS process to provide three reconfigurable data conversions that correspond to a low-power resistance-to-digital converter (RDC), a 12-bit successive approximation register (SAR) analog-to-digital converter (ADC), and a 16-bit delta-sigma modulator. For functional feasibility, a wireless sensor system prototype that included in-house microelectromechanical (MEMS) sensing devices and commercial device products was manufactured and experimentally verified to detect a variety of hazardous gases.

Keywords: heterogeneous gas; microelectromechanical (MEMS) device; multi-sensor; readout integrated circuit (ROIC); reconfigurable resolution; suspended nanowire; wireless sensor interface.