Growth of zinc oxide sensitive layer on microcantilever surface for gas sensor application

Microcantilever-based sensors have been demonstrated to be a high sensitive sensor in sensing application areas of chemistry, physics, biology, and biomedical. To determine the sensor selectivity, the microcantilever surface must be coated by a sensitive layer. In this work, zinc oxide (ZnO) is prepared on the microcantilever surface as a sensitive layer by employing a crystal growth method. To confirm the elemental of ZnO sensitive layer, the coated microcantilever surface is characterized by energy dispersive spectroscopy (EDS). Next, we investigate the response of microcantilever sensor to CO₂ gas in dynamic mode operation. The results show that the microcantilever sensitively responds the gas, which is indicated by the change of resonance frequency. Moreover, the consistent sensing behavior with certain resonance frequency shift due to gas response over repetitive cycles is found. The quite small of response and recovery times indicate that the sensing performance of the microcantilever with ZnO sensitive layer has high repeatablility and high reproducibility.