Humidity sensing properties of sprayed thin film MWCNT-PVP composites

We studied the change of electrical resistance under climate controlled conditions of thin film coatings which are composed of multi-walled carbon nanotubes (MWCNTs) and polyvinylpyrrolidone (PVP). The presented films are characterized via DC resistance measurements in a climate control chamber with different humidity levels. Our measurements show significant increase of relative resistance change with decreasing carbon nanotube loadings in the nanocomposite films, especially for higher air humidity levels. Resistance changes >; 400 % of a 10 wt. %-MWCNT-PVP film in a relative humidity range from 40 - 70 % have been measured.