Integration of ZnO nanostructures with MEMS for ethanol sensor

An ethanol sensor incorporating nanostructured zinc oxide film on integrated MEMS platform is reported. A salient feature of the sensor is its lower operating temperature, which has been achieved due to the use of nanostructured material as sensing layer in addition to a catalyst free synthesis technique to grow nanostructures. A suitably designed nickel microheater has been integrated with the sensor. The sensor was tested for various volatile organic compounds (VOCs). The sensor is sensitive and selective to ethanol vapors at operating temperature of 100 degrees C. The change in sensor resistance is significantly enhanced in the sensor prepared using combination of ZnO nanoflakes with nanowires as sensing film as compared to a similar sensor having a thin film of ZnO as sensing layer. The dynamic response of the sensor was also studied. (C) 2011 Elsevier B.V. All rights reserved.