Our previous study has proved that piezo-cantilever coated with temperature-responsive polymer gel can measure swelling ratio of the polymer in solution by piezo-impedance measuring technology. However, the sensitivity and accuracy of the piezo-cantilever transducer is related to the vibration modes actuated by the piezoelectric cell. The bending mode seems not available to work in solution as its amplitude is attenuated greatly and causes noise easily in solution. In this study, the longitudinal mode of piezo-cantilever transducer has been studied to detect physical changing due to the temperature-sensitive polymer gel. The impedance responses to variation of physical properties such as length, thickness and density of the polymer gel have been investigated. The results show that for a certain longitudinal mode, variation of length of the polymer can be neglected. The swelling ratio of the piezo-cantilever transducer is obtained theoretically. Finally. A new type of piezo-cantilever transducer is proposed that is more convenient in practice.

Date Published: 21 March 2006
PDF: 6 pages
Proc. SPIE 6040, ICMIT 2005: Mechatronics, MEMS, and Smart Materials, 60402N (21 March 2006); doi: 10.1117/12.664273

Published in SPIE Proceedings Vol. 6040:
ICMIT 2005: Mechatronics, MEMS, and Smart Materials
Yunlong Wei; Kil To Chong; Takayuki Takahashi; Shengping Liu; Zushu Li; Zhongwei Jiang; Jin Young Choi, Editor(s)