Advanced Micro- and Nano-Gas Sensor Technology: A Review

Abstract

Micro- and nano-sensors lie at the heart of critical innovation in fields ranging from medical to environmental sciences. In recent years, there has been a significant improvement in sensor design along with the advances in micro- and nano-fabrication technology and the use of newly designed materials, leading to the development of high-performance gas sensors. Advanced micro- and nano-fabrication technology enables miniaturization of these sensors into micro-sized gas sensor arrays while maintaining the sensing performance. These capabilities facilitate the development of miniaturized integrated gas sensor arrays that enhance both sensor sensitivity and selectivity towards various analytes. In the past, several micro- and nano-gas sensors have been proposed and investigated where each type of sensor exhibits various advantages and limitations in sensing resolution, operating power, response, and recovery time. This paper presents an overview of the recent progress made in a wide range of gas-sensing technology. The sensing functionalizing materials, the advanced micro-machining fabrication methods, as well as their constraints on the sensor design, are discussed. The sensors’ working mechanisms and their structures and configurations are reviewed. Finally, the future development outlook and the potential applications made feasible by each category of the sensors are discussed.

Hierarchical Ordered Dual‐Mesoporous Polypyrrole/Graphene Nanosheets as Bi‐Functional Active Materials for High‐Performance Planar Integrated System of Micro‐Supercapacitor and Gas Sensor

“…[ 6–9 ] In particular, for body‐attachable and portable detection of gas pollutants (e.g., NH 3 , one of the most common gases in industry, agriculture, and our daily life), [ 10–12 ] the MSC‐gas sensor integrated system represents a more and more important core technique of swiftly and reversibly monitoring surrounding gas in real‐time to control industrial processes, reduce environmental pollution, and manage physical health. [ 13–15 ] So far, most integrated systems are assembled with serial devices based on multiple mono‐functional materials. [ 7,9,16–18 ] For instance, a MSC‐gas sensor integrated system was reported, based on polyaniline‐wrapped carbon nanotube MSC as energy storage unit and graphene gas sensor as energy consumption device.…”

Mass Sensors Based on Capacitive and Piezoelectric Micromachined Ultrasonic Transducers—CMUT and PMUT

“…Microelectromechanical system (MEMS)-based sensors are introduced as high-performance detectors due to their sensing capabilities at the micro and nanoscale levels and their potential for integration with wearable electronics [1,2]. These gas sensors can employ various detection techniques using resistivity, optical properties, acoustic measurements and mass detection [3].…”

“…Amongst them, the mass detection method is reported as an emerging candidate due to its stellar performance in detecting low gas concentration levels [3]. MEMS-based mass resonant sensors benefit from a low power consumption, a high selectivity and a low limit of detection (LOD) whilst being integrable in a wide range of applications [1]. Amongst them, micromachined ultrasonic transducers (MUT) are shown as potential candidates in sensing applications [4][5][6].…”

Detection Principles of Temperature Compensated Oscillators with Reactance Influence on Piezoelectric Resonator

“…The quartz oscillator, in particular, is uniquely suited for the manufacture of frequency selection or frequency control devices [1][2][3]. On the other hand, these oscillators can be used for the detection of various physical quantities based on the frequency change that can be triggered by mechanical influence on the crystal [4] or electrical influence on its substitute electrical model [1,5]. The purpose of this study is to provide an overview of various ways of detection of physical quantities using oscillators with a piezoelectric crystal (as an oscillating element) and reactance connected in series or in parallel.…”