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

Abstract

Microcantilever-based sensorshave 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 CO 2 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.

Highly Sensitive Self-Actuated Zinc Oxide Resonant Microcantilever Humidity Sensor

“…ZnO is a versatile gas-sensor receptor material that has been employed in a variety of unique gas-sensor devices, such as chemiresistive, − resonant microcantilever, − , and quartz crystal microbalance (QCM) type sensors. − It can serve as the cantilever structural layer because of its comparable elastic modulus to silicon. − Moreover, its deposition by AP-SALD and growth behavior at atmospheric pressures (i.e., open-air) are well understood. − Utilizing AP-SALD and other conventional fabrication techniques ensures reproducibility of the produced cantilever device at scale. The reduction in cantilever thickness to the nanoscale reduces its overall mass, making it more susceptible to small mass changes via gas adsorption.…”