Credit: Meng Li et al.
Researchers from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences have developed a smart electronic nose (e-nose) that can detect target gas molecules within one second.
The e-nose utilizes a unique self-heating strategy to modulate the nose to provide accuracy selectivity for target gasses. In the study, published in ACS Sensors, researchers made significant advances at overcoming the lack of selectivity in other semiconductor-based gas sensors. Previously, these sensors faced several challenges hindering their ability to be used for early warning detection of lethal or explosive gasses.
To overcome these, the researchers employed a novel approach for temperature control and modulation. The researchers relied on a tungsten trioxide (WO3) nanorod film that was developed using oblique angle deposition (OAD). This nanorod film not only served as a sensing layer but also as a stable self-heating mechanism. With a thermal relaxation time of around 20 μs, the sensor can utilize self-heating temperature modulation to generate a sufficient electrical response.
The advancements developed by the researchers allowed for the accurate determination of 12 gas molecules in under 1 second, a response time that is an order faster than current e-noses. Additionally, the sensors are optimized to accurately and instantaneously identify the target gasses in ambient air backgrounds.
Thanks to the advances made to the response time and selectivity for target gasses, the sensors could have applications in security and public health thanks to their accurate and rapid detection of target lethal or explosive gasses.