Self-Sustaining Square-Extensional Mode Resonator Oscillator for Mass Sensing in Liquid

Proceedings

Lee, Joshua En-Yuan¹  Begum, Habiba²  Ali, Abid³ 

[1] Author to whom correspondence should be addressed.;Department of Electronic Engineering, City University of Hong Kong, Hong Kong 999077, China;State Key Laboratory of Terahertz and Millimeter Waves, City University of Hong Kong, Hong Kong 999077, China

关键词: MEMS resonator;    MEMS oscillator;    thin-film piezoelectric-on-silicon (TPoS);    liquid phase sensing;   

DOI  :  10.3390/proceedings2130976

学科分类：社会科学、人文和艺术（综合）

来源: mdpi

【 摘 要 】

We present a 5.41 MHz square-extensional (SE) mode resonator in closed-loop oscillation for resonant mass sensing in the liquid phase. The resonator has been fabricated in piezoelectric thin film aluminum nitride (AlN) on silicon (Si). The strain profile of the SE mode allows for higher electromechanical coupling efficiency using piezoelectric transduction to lower the motional resistance (Rm) given the expected low quality factors (Q) in liquid (136 compared to 942 in air). By locking the device into self-sustained oscillation, the minimum detectable frequency shift is reduced from 3680 ppm (open-loop in water) to 8.76 ppm (closed-loop in air).

【 授权许可】

CC BY