A Surface Acoustic Wave Ethanol Sensor with Zinc Oxide Nanorods

الملخص EN

Surface acoustic wave (SAW) sensors are a class of piezoelectric MEMS sensors which can achieve high sensitivity and excellent robustness.

A surface acoustic wave ethanol sensor using ZnO nanorods has been developed and tested.

Vertically oriented ZnO nanorods were produced on a ZnO/128∘ rotated Y-cut LiNbO3 layered SAW device using a solution growth method with zinc nitrate, hexamethylenetriamine, and polyethyleneimine.

The nanorods have average diameter of 45 nm and height of 1 μm.

The SAW device has a wavelength of 60 um and a center frequency of 66 MHz at room temperature.

In testing at an operating temperature of 270C∘ with an ethanol concentration of 2300 ppm, the sensor exhibited a 24 KHz frequency shift.

This represents a significant improvement in comparison to an otherwise identical sensor using a ZnO thin film without nanorods, which had a frequency shift of 9 KHz.