Microheater Integrated Nanotube Array Gas Sensor for Parts-Per-Trillion Level Gas Detection and Single Sensor-Based Gas Discrimination

Abstract

Real-time monitoring of health threatening gases for chemical safety and human health protection requires detection and discrimination of trace gases with proper gas sensors. In many applications, costly, bulky, and power-hungry devices, normally employing optical gas sensors and electrochemical gas sensors, are used for this purpose. Using a single miniature low-power semiconductor gas sensor to achieve this goal is hardly possible, mostly due to its selectivity issue. Herein, we report a dual-mode microheater integrated nanotube array gas sensor (MINA sensor). The MINA sensor can detect hydrogen, acetone, toluene, and formaldehyde with the lowest measured limits of detection (LODs) as 40 parts-per-trillion (ppt) and the theoretical LODs of ∼7 ppt, under the continuous heating (CH) mode, owing to the nanotubular architecture with large sensing area and excellent surface catalytic activity. Intriguingly, unlike the conventional electronic noses that use arrays of gas sensors for gas discrimination, we discovered that when driven by the pulse heating (PH) mode, a single MINA sensor possesses discrimination capability of multiple gases through a transient feature extraction method. These above features of our MINA sensors make them highly attractive for distributed low-power sensor networks and battery-powered mobile sensing systems for chemical/environmental safety and healthcare applications.

Wearable Sensor-Based Monitoring of Environmental Exposures and the Associated Health Effects: A Review

“…Moreover, studies on metal oxide (MOX) semiconductor gas sensors have drawn much attention due to their low costs, trim sizes, and reasonable life span. Some studies have developed prototypes of MOX-based gas sensors to measure a single VOC or multiple VOC components with sensor arrays [ 87 , 88 , 89 ]. In addition, sensor-based methods have been recently developed for per- and polyfluoroalkyl substances (PFAS) detection, such as small molecule complexation and assay-based methods, nanoparticle-based methods, molecularly imprinted polymer (MIP)-based methods, optical fiber-based method, and immunosensor-based methods [ 90 ].…”

Technology Roadmap for Flexible Sensors

“…Overall, recent advances in flexible roomtemperature gas sensor arrays have achieved lower power consumption, reduced fabrication cost, and greater wearability without sacrificing sensing performance. 142,151−155 Although machine learning algorithms capable of higher prediction accuracy can compensate for sensor selectivity shortfalls, 151,156,157 improving the specificity of each sensor remains a critical challenge.…”

“…A recent approach achieved the fabrication and utilization of an array of 108 graphene-based sensors functionalized with 36 chemical receptors for the discrimination of 6 gas species within a minute, shedding light on rapid VOC detection using large-scale sensor arrays. Overall, recent advances in flexible room-temperature gas sensor arrays have achieved lower power consumption, reduced fabrication cost, and greater wearability without sacrificing sensing performance. ,− Although machine learning algorithms capable of higher prediction accuracy can compensate for sensor selectivity shortfalls, ,, improving the specificity of each sensor remains a critical challenge.…”

Temperature‐Modulated Selective Detection of Part‐per‐Trillion NO2 Using Platinum Nanocluster Sensitized 3D Metal Oxide Nanotube Arrays

“…[8][9][10][11] However, NO 2 always exists under the presence of other interfering gases, such as formaldehyde (FA), toluene, acetone, and SO 2 , and the sensitive and selective detection trace amount of NO 2 among the interfering gases remains a bottleneck challenge. Chemiresistive gas sensors made of metal-oxide semiconductors, such as tin oxide (SnO 2 ) [12][13][14] and zinc oxide (ZnO), [15][16][17][18] possess a number of highly attractive merits, including small formfactor and being integratable with other semiconductor devices, long life-time, and low cost. Thus, they are playing the critical roles in a smart and sustainable city for safety and healthy monitoring.…”