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Sol–gel processed alumina (Al2O3) thin film has been investigated for sensing moisture. The sensor was based on ordered nanoporous Al2O3 thin film, which consisted of gold electrodes on both sides of the film forming parallel plate capacitor. Alumina substrate was used for supporting thin film moisture sensor. Hydrophilicity was achieved by controlling the surface energy of the substrate and polymer (polyvinyl alcohol (PVA)) optimization was done for developing rigid thin film over it. A high change in capacitance was observed as the moisture level increased from 5 ppmV to 500 ppmV. Scanning electron microscopy (SEM) results revealed that pores were distributed uniformly throughout the sample, which enhanced the adsorption of water molecule over the film. X-ray diffraction (XRD) study clearly confirmed the gamma (γ) phase of alumina thin film. It was found that the sensitivity of our sensor was suitable for commercial application.


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Polymer optimization for the development of low-cost moisture sensor based on nanoporous alumina thin film

Show Author's information Manju PANDEYaPrabhash MISHRAaDebdulal SAHAbS. S. ISLAMa,*( )
Nano-Sensor Research Laboratory, F/O Engineering and Technology, Jamia Millia Islamia (Central University), New Delhi, India
Sensors and Actuators Division, Central Glass & Ceramic Research Institute, 196 Raja S. C. Mullick Road, Kolkata 700032, India

Abstract

Sol–gel processed alumina (Al2O3) thin film has been investigated for sensing moisture. The sensor was based on ordered nanoporous Al2O3 thin film, which consisted of gold electrodes on both sides of the film forming parallel plate capacitor. Alumina substrate was used for supporting thin film moisture sensor. Hydrophilicity was achieved by controlling the surface energy of the substrate and polymer (polyvinyl alcohol (PVA)) optimization was done for developing rigid thin film over it. A high change in capacitance was observed as the moisture level increased from 5 ppmV to 500 ppmV. Scanning electron microscopy (SEM) results revealed that pores were distributed uniformly throughout the sample, which enhanced the adsorption of water molecule over the film. X-ray diffraction (XRD) study clearly confirmed the gamma (γ) phase of alumina thin film. It was found that the sensitivity of our sensor was suitable for commercial application.

Keywords:

sol–gel, dip-coating, polyvinyl alcohol (PVA), nanoporous, hydrophilicity, moisture sensor
Received: 18 July 2013 Revised: 16 August 2013 Accepted: 26 August 2013 Published: 04 December 2013 Issue date: December 2013
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Publication history
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Publication history

Received: 18 July 2013
Revised: 16 August 2013
Accepted: 26 August 2013
Published: 04 December 2013
Issue date: December 2013

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© The author(s) 2013

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