doi:10.1038/nindia.2018.38 Published online 22 March 2018
Researchers have synthesised a flexible sensor that can detect traces of ethanol gas in atmosphere, making it potentially useful for making wearable gas-sensing devices1.
Existing ethanol gas sensors operate at high temperatures, requiring complex processes to make them. Besides, they are not flexible and display low sensitivity. Most of them are unstable and expensive.
To make a highly sensitive ethanol gas sensor, scientists from the Bharathiar University in Coimbatore, India, deposited polyvinyl-alcohol-coated multiwalled carbon nanotubes onto a cotton fabric. They then tested its efficiency in detecting ethanol gas.
When exposed to an ethanol gas concentration of 100 parts per million (ppm) at room temperature, the sensor exhibited excellent sensitivity. The sensor showed a 13-fold higher gas sensitivity than the uncoated nanotube-based sensor.
The sensor retained its efficiency to detect ethanol gas after long, repeated on-and-off cycles, indicating its stability. It also showed higher sensitivity to ethanol gas than to other gases such as ammonia, acetone, benzene, cyclohexane, methanol, toluene and xylene.
The sensor was able to detect ethanol gas in 24 seconds and it could even detect ethanol gas as low as 9.17 ppm, showing its great potential to be used in the food-producing industries and biomedical fields.
1. Maity, D. et al. Polyvinyl alcohol wrapped multiwall carbon nanotube (MWCNTs) network on fabrics for wearable room temperature ethanol sensor. Sensor. Actuator. B. Chem.261, 297-306 (2018)