Investigation of the Frequency Shift of a SAD Circuit Loop and the Internal Micro-Cantilever in a Gas Sensor

Sensors

Liu Guan²  Jiahao Zhao¹  Shijie Yu²  Peng Li² 

[1] Department of Precision Instruments and Mechanics, Tsinghua University, Beijing 100084, China;

关键词: micro-cantilever;    gas sensor;    frequency shift;    oscillator loop;   

DOI  :  10.3390/s100707044

来源: mdpi

【 摘 要 】

Micro-cantilever sensors for mass detection using resonance frequency have attracted considerable attention over the last decade in the field of gas sensing. For such a sensing system, an oscillator circuit loop is conventionally used to actuate the micro-cantilever, and trace the frequency shifts. In this paper, gas experiments are introduced to investigate the mechanical resonance frequency shifts of the micro-cantilever within the circuit loop(mechanical resonance frequency, MRF) and resonating frequency shifts of the electric signal in the oscillator circuit (system working frequency, SWF). A silicon beam with a piezoelectric zinc oxide layer is employed in the experiment, and a Self-Actuating-Detecting (SAD) circuit loop is built to drive the micro-cantilever and to follow the frequency shifts. The differences between the two resonating frequencies and their shifts are discussed and analyzed, and a coefficient α related to the two frequency shifts is confirmed.

【 授权许可】

CC BY   
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