Electrical behavior of devices composed by dielectrophoretically deposited carbon nanotubes for gas sensing applications

Miniaturized gas sensors have been developed with a view to integrating them into smart systems for environment control, for example. Intensive research has been focused on investigating new sensing materials, such as carbon nanotubes (CNT) because of their promising characteristics, but there are challenges related to their application in commercial devices such as sensitivity, compatibility, and complexity of miniaturization, among others. We report the study of the electrical behavior of multi-walled carbon nanotubes (MWCNT) material deposited between interdigitated electrode structures by means of dielectrophoresis (DEP), which is a simple and cost-effective method. The devices were fabricated by varying the DEP process time. Remarkable changes in their electric resistance in the presence of water vapor were noticed as a function of MWCNT quantities deposited. These results indicate that the charge exchange mechanisms on the CNT surface play an important role in the material resistivity.