A compact wireless gas sensor using a carbon nanotube/PMMA thin film chemiresistor

Abstract

The design and development of a compact wireless gas sensor with a surface modified multiwalled carbon nanotube (f-CNT) chemiresistor as the sensing element is presented in this paper. f-CNT/polymer composite sensing film is patterned on a printed circuit board and is integrated to the wireless system. The change in resistance of the CNT/polymer composite film due to exposure of different gases is utilized as the principle of this gas sensor. The response for different organic vapors are evaluated and it is observed that the f-CNT/PMMA composite film shows fast response and change in resistance of the order of 10 2-10 3 due to its surface modification.

Influence of carbon nanotube clustering on the electrical conductivity of polymer composite films

“…Electrical conductivity of PSF-CNT films loaded with different weight fractions (0.05-0.75% w/w) of MWCNTs was measured at room temperature using a Fluke electrometer 3 . The electrometer is capable of measuring DC electrical resistance up to 1 TΩ.…”

“…In recent years, a great deal of attention has been paid to the electrical properties of such composites, given the great promises that these materials hold as multifunctional materials in the area of electronics, sensors, and actuators [1][2][3][4]. Electrical conductivity of CNT-polymer nanocomposites using very low CNT weight loadings typically reaches the level of semiconductors (~0.001-0.1 S/m) [4][5][6][7].…”

Nanocomposite Films for Gas Sensing

“…The extent of swelling and hence the electrical response depends on the solubility of the polymer in the solvent. In addition, CNT surface that contains polar functional groups can also adsorb organic solvent molecules (Abraham, 2004). Hieu et al investigated the effects of film thickness, annealing temperature, and SWCNTs content on gas-sensing response of PPY-SWCNTs nanocomposite for detection of NH 3 gas at room temperature.…”

A review on carbon nanotubes in an environmental protection and green engineering perspective

“…Contrary to the PEI coated sensor, a CNT-based gas sensor coated with Nafion (a polymeric perfluorinated sulfonic acid ionomer) allowed higher selectivity for sensing NH 3 owing to the blocking of NO 2 on CNTs. Fabrication of a compact wireless gas sensor based on a CNT/poly(methyl methacrylate) (PMMA) composite chemiresistor by Abraham et al (2004) also showed an improvement in sensitivity upon exposure to volatile organic compounds likes dichloromethane, chloroform and acetone vapor. Even though CNT-based gas sensors exhibit strong competition for conventional metal oxide sensors, non-stop developments have been carried out to improve the conventional gas sensor.…”