Abstract
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.