PANI/MWCNT based humidity sensor

Hammad R Humud

doi:10.30723/ijp.v15i33.147

Abstract

Polyaniline Multi wall Carbon nanotube (PANI/MWCNTs) nanocomposite thin films have been prepared by Plasma jet polymerization at low frequency on glass substrate with preliminary deposited aluminum electrodes to form Al/PANI-MWCNT/Al surface-type capacitive humidity sensors, the gap between the electrodes about 50 μm and the MWCNTs weight concentration varied between 0, 1, 2, 3, 4%. The diameter of the MWCNTs was in the range of 8-15 nm and the length 10-55 μm. The capacitance-humidity relationships of the sensors were investigated at humidity levels from 35 to 90% RH. The electrical properties showed that the capacity increased with increasing relative humidity, and that the sensitivity of the sensor increases with the increase of the additive (MWCNTs); while each of the response time and the recovery time increasing with concentration. The change in MWCNTs concentration leads to a change in the energy gap as well as the initial capacity. The capacitance increases linearly with the relative humidity at MWCNTs concentration of 3% for thus the possibility of manufacturing humidity sensor with good specifications at this concentration.

Highlights

Carbon nanotubes (CNTs) have attracted considerable attention since their discovery by Iijima in 1991[1].There was great interest in exploring and exploiting their unique characteristics for various applications [2,3]
PANI / MWCNTS nanocomposite thin films were prepared with different MWCNTS weight concentration 1%, 2%, 3%, and 4%
In order to determine the sensor capacitance dependence on the PANI\MWCNT concentration, five sensors were fabricated with MWCNT concentrations of 0wt%, 1wt%, 2wt%, 3wt% and 4wt%

Summary

Introduction

Carbon nanotubes (CNTs) have attracted considerable attention since their discovery by Iijima in 1991[1].There was great interest in exploring and exploiting their unique characteristics for various applications [2,3]. Humidity can be determined by methods and devices such as psychrometric (wet- and drybulb hydrometers), mechanical hygrometers (exploiting the change in dimensions of porous materials such as paper and hair), dew point sensors, electrolytic sensor, spectroscopic sensors and hygrometers where capacity or resistance are measured.

Results

Conclusion