A novel creation of thread-based ammonia gas sensors for wearable wireless security system

Thread-based gas sensor based on poly (styrenecomaleic acid) partial isobutyl/methyl mixed ester and multi-walled carbon nanotube (PSE/MWCNT) nanocomposite for NH₃ detection has been designed and created from two simple processes; crochet and immersion (dip) coating processes. This new dimension of fabric-based gas sensors fabrication is suitable for integrating directly into the flexible substrates to be applied as wearable gas detection instruments such as gas-protective clothing, gas safety shoes and gas masks. Soft materials which do not irritate the wearer have been used for this sensor. This work opens a new perspective that overcomes the well-known limitation for creating a fabric-based gas sensor such as the complexity of the production process, high cost and high power consumption in operating. Thus it leads to an innovative integration between science and smart art. As a result, we can make a cheap wireless gas detector based on Xbee communication technology, with low power consumption. This sensor was tested for its selectivity and sensitivity performance toward several volatile compounds, namely ammonia, pyridine, acetic acid, ethanol and acetone. The results revealed that this sensor has higher sensitivity and specificity to NH₃ than other gases. It is possible to monitor NH₃ until it reaches a concentration of 5 ppm and also has the ability to recover as well.