摘要
A novel capacitance-type relative humidity(RH) sensor based on multi-wall carbon nanotube/SiO(MWCNTs/SiO) composite film is reported.Details of the fabrication process,possible sensing mechanism and sensing characteristics,such as linearity and sensitivity,are described.The capacitance of the MWCNTs/SiOcomposite film shows typical concentration percolation behavior with increasing MWCNT loading.At loadings below the percolation threshold(1.842wt%),the sensor capacitance increases obviously with increasing MWCNTs. The water condensed in the MWCNTs/SiOlayer can lower the percolation threshold and increase the sensor capacitance.The sensor with MWCNT concentration of 1wt%has the best properties.The sensor has a humidity sensitivity of about 673 pF/%RH and a linearity correlation of 0.98428.The response time of the sensor to RH is about 40 s and the recovery time is about 2 s.
A novel capacitance-type relative humidity（RH） sensor based on multi-wall carbon nanotube/SiO2 （MWCNTs/SiO2） composite film is reported.Details of the fabrication process,possible sensing mechanism and sensing characteristics,such as linearity and sensitivity,are described.The capacitance of the MWCNTs/SiO2 composite film shows typical concentration percolation behavior with increasing MWCNT loading.At loadings below the percolation threshold（1.842wt%）,the sensor capacitance increases obviously with increasing MWCNTs. The water condensed in the MWCNTs/SiO2 layer can lower the percolation threshold and increase the sensor capacitance.The sensor with MWCNT concentration of 1wt%has the best properties.The sensor has a humidity sensitivity of about 673 pF/%RH and a linearity correlation of 0.98428.The response time of the sensor to RH is about 40 s and the recovery time is about 2 s.
