Ultra-Low-Power Smart Electronic Nose System Based on Three-Dimensional Tin Oxide Nanotube Arrays

Abstract

In this work, we present a high-performance smart electronic nose (E-nose) system consisting of a multiplexed tin oxide (SnO) nanotube sensor array, read-out circuit, wireless data transmission unit, mobile phone receiver, and data processing application (App). Using the designed nanotube sensor device structure in conjunction with multiple electrode materials, high-sensitivity gas detection and discrimination have been achieved at room temperature, enabling a 1000 times reduction of the sensor's power consumption as compared to a conventional device using thin film SnO. The experimental results demonstrate that the developed E-nose can identify indoor target gases using a simple vector-matching gas recognition algorithm. In addition, the fabricated E-nose has achieved state-of-the-art sensitivity for H and benzene detection at room temperature with metal oxide sensors. Such a smart E-nose system can address the imperative needs for distributed environmental monitoring in smart homes, smart buildings, and smart cities.

Indoor Air Pollution, Related Human Diseases, and Recent Trends in the Control and Improvement of Indoor Air Quality

“…This concept is anticipated to serve as a model for future IAQ-monitoring devices. In other research, Chen et al developed a high-performance smart E-nose system comprising a multiplexed tin oxide (SnO 2 ) nanotube sensor array, a read-out electronic circuit, a mobile phone receiver, a wireless data transmission unit, and a data processing application [181]. Compared with conventional devices, this nanotube sensor exhibited higher sensitivity gas detection and discrimination at room temperature, owing to the use of nanotube sensors possessing a large surface area for interaction with gas molecules.…”

“…Illustration of the proposed electronics nose (E-nose) system architecture (A); the proposed E-nose application in future smart buildings (B); primitive concept design of Smart-Air (C); and a smart ventilation system for optimizing indoor air quality (IAQ) Levels in buildings (D). Reproduced with permission from[180,181,183,184].…”

Printable Fabrication of a Fully Integrated and Self‐Powered Sensor System on Plastic Substrates

“…On the other hand, the system demonstrated in this work is operated in a low‐power mode, and thus the power consumption on interconnects is nearly negligible. Also, sensors with higher sensitivity can be realized with strategies such as nanoengineering by applying 3D porous templates or surface decoration with noble metal nanoparticles . Recent studies also demonstrate the strategies to achieve flexible solar cells (e.g., perovskite solar cells) in printable manners with novel device structures and combination of different printing techniques, and thus a fully printable and wearable self‐powered fabricated on flexible substrate is also promising.…”

“…SnO 2 as a n‐type semiconductor, is one of the most commonly used material for gas sensing mainly due to its low cost, stability, and repeatability . While metal oxide sensors normally require high operation temperature (over 200 °C) to achieve high sensitivity and fast recovery, recent studies demonstrated the SnO 2 has the capability for volatile organic compounds detection under room temperature, which eliminate the integration of heaters and thermal isolation units . Especially for portable and wearable electronics, room temperature operational sensors are highly desirable for device miniaturization and long cruising time without extra power consumption for heaters .…”

“…While metal oxide sensors normally require high operation temperature (over 200 °C) to achieve high sensitivity and fast recovery, recent studies demonstrated the SnO 2 has the capability for volatile organic compounds detection under room temperature, which eliminate the integration of heaters and thermal isolation units . Especially for portable and wearable electronics, room temperature operational sensors are highly desirable for device miniaturization and long cruising time without extra power consumption for heaters . As gas sensing is a surface reaction dominated process, the material morphology and uniformity have large influence on the sensor performance .…”