Inkjet printing of polymer functionalized CNT gas sensor with enhanced sensing properties

We report on fully inkjet printed carbon nanotubes gas sensors on flexible substrates with improved ethanol sensing characteristics. The sensors were fabricated via two simple steps: printing the electrodes and the carbon nanotubes based - active layer. Carbon nanotubes were functionalized with carboxylic acid (COOH) and poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS). The performance analysis shows a significant enhancement in the sensitivity of the sensor with polymer wrapped nanotubes in comparison with the oxidized nanotubes, with enhancement factors greater than 2.5. Moreover, a remarkable improvement in the sensor response and recovery times after polymer functionalization is noted which bodes well for fully printable environmental sensors on flexible plastic circuits.