An elastic, wearable gas sensor for environmental sensing has been developed and tested by researchers at Penn State, Northeastern University and five universities in China.
The sensing unit integrates a freshly developed laser-induced graphene foam product with a distinct form of molybdenum disulfide and reduced-graphene oxide nanocomposites.
Nitrogen dioxide is a toxic gas emitted by cars that can aggravate the lungs at low concentrations and result in illness and death at high concentrations.
When the scientists added molybdenum disulfide and decreased graphene oxide precursors to the container, the nanocomposites formed structures in the little spaces between the salt crystals. They tried this with a range of different salt sizes and tested the sensitivity on standard interdigitated electrodes, in addition to the recently established laser-induced graphene platform. When the salt was eliminated by dissolving in water, the researchers identified that the tiniest salt crystals enabled the most sensitive sensing unit.
” We have actually done the screening to 1 part per million and lower concentrations, which could be 10 times much better than conventional design,” states Huanyu Larry Cheng, assistant teacher of engineering science and mechanics and materials science and engineering. “This is a rather modest complexity compared to the best standard technology which needs high-resolution lithography in a cleanroom.”
Ning Yi and Han Li, doctoral students at Penn State and co-authors on the paper in Products Today Physics, added, “The paper examined the noticing efficiency of the reduced graphene oxide/moly disulfide composite. More significantly, we find a method to enhance the level of sensitivity and signal-to-noise ratio of the gas sensor by controlling the morphology of the composite material and the configuration of the sensor-testing platform. We think the stretchable nitrogen dioxide gas sensing unit may find applications in real-time environmental tracking or the healthcare industry.”