Acetone detection using thin tungsten oxide (WO3) film based gas sensor

Abstract

Acetone being a volatile organic compound is found in human breath. Non-invasive breath analysis for detection of diabetes has gained remarkable attention for the past few years. Human breath has ample of volatile organic compounds pertaining to numerous diseases in the body. Acetone in breath has been proven to be an important biomarker for diagnosis of diabetes through breath. Here, tungsten oxide (WO3) thin films of nanometer thickness have been used for this purpose. The detector films are sputtered over silicon dioxide layer and corresponding connections are made over the film to measure the resistance change. Acetone, being a reducing gas, reduces the resistance of the film as it comes in contact. Different concentrations in parts per million (ppm) have been tested on these nanometer films having thickness of 100 nm over a chip size of 5 mm x 5 mm, as low as 1.2 ppm. Optimum temperature has also been computed to be 300 oC. The topography of film has been characterized by atomic force microscopy (AFM) and a mean grain size of 24.1 nanometers has been observed.