Polyaniline based stable humidity sensor operable at room temperature

Facile Fabrication of an Ammonia-Gas Sensor Using Electrochemically Synthesised Polyaniline on Commercial Screen-Printed Three-Electrode Systems

“…In all these cases, PANI is synthesised via a chemical polymerisation method. deposited on interdigitated electrodes with multiple "fingertips" [8,9,21,30,36] (Figure 1a), (ii) a PANI film on glass substrates [40] (Figure 1b), (iii) a PANI pellet connected by wires [38] (Figure 1c), (iv) a PANI film deposited on two electrodes made of different metals [39] ( Figure 1d) or (v) PANI in a screen-printed two-electrode system [37] ( Figure 1e). The deposition of PANI on such electrodes is usually completed with drop-casting [9,21,30,37,39], spin-coating [8,41] and layer-by-layer assembly [41].…”

“…We report on a direct electrodeposition procedure for PANI on a Figure 1. Polyaniline (PANI)-based ammonia/humidity gas sensors: (a) interdigitated electrodes [8,9,21,30,36]; (b) film [40]; (c) pellet [38]; (d) two different metal electrodes [39]; (e) screen-printed two-electrode system [37].…”

“…Moreover, various configurations have been used to monitor the changes in the PANI’s resistance [ 8 , 9 , 21 , 30 , 36 , 37 , 38 ] or impedance [ 39 ] in the presence of NH 3 gas. They consist of (i) two-point resistivity measurements that are usually made using either PANI deposited on interdigitated electrodes with multiple “fingertips” [ 8 , 9 , 21 , 30 , 36 ] ( Figure 1 a), (ii) a PANI film on glass substrates [ 40 ] ( Figure 1 b), (iii) a PANI pellet connected by wires [ 38 ] ( Figure 1 c), (iv) a PANI film deposited on two electrodes made of different metals [ 39 ] ( Figure 1 d) or (v) PANI in a screen-printed two-electrode system [ 37 ] ( Figure 1 e). The deposition of PANI on such electrodes is usually completed with drop-casting [ 9 , 21 , 30 , 37 , 39 ], spin-coating [ 8 , 41 ] and layer-by-layer assembly [ 41 ].…”

A resistive sensor for humidity detection based on cellulose/polyaniline

“…It is of great interest in device applications due to stability of doped/undoped states, ease of structural modification and solution processability. 9,14–19 Its winning property is the simplicity of preparation that allows the functionalization of commonly used materials such as fabrics and paper. 20–24 Moreover, when exposed to humidity the effective resistance of PANI film changes due to the formation of hydrogen bonds between water molecules and the nitrogen present in the amine group.…”

“…17,25,26 The conductivity of PANI increases with increasing humidity due to continuous proton exchange and this makes PANI-based derivatives and composites attractive candidates for humidity sensing materials. 3,9,17,19,26…”