Self-Heating Gas Detector
A smart electronic nose (e-nose), or gas sensor, has been developed which detects gasses in less than a second. A recent study published in ACS Sensors announced this new gas detector by a research team led by Prof. Meng Gang from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences. It utilizes a self-heating modulation process to accurately detect different types of gas molecules within just a second.
Existing Gas Sensors Have Limitations
Major advancements have been made in gas molecule discrimination using an e-nose composed of non-selective gas sensors. However, obtaining adequate molecular attributes in a short time has remained a major obstacle, which has reduced the early warning systems using an e-nose for lethal or explosive gases.
New Device Uses an Integrated Heating System
In this new study, a creative approach for temperature control and modulation was invented as an alternative to the conventional method using external heaters. A tungsten trioxide (WO3) nanorod film was used as both a sensitive sensing layer and a stable self-heating layer. Due to the ultrafast (～20 μs) thermal relaxation time, the sensor can produce adequate electrical responses through self-heating temperature modulation. This improvement has led to the accurate detection of 12 gas molecules within 0.5–1 seconds, which is about ten times faster than the currently available e-noses. A smart wireless e-nose system was also created to enable accurate and instant identification of specific gases in ordinary air. This development shows the potential applications of the e-nose for security and public health
Source: Phys.org
