Title :
Antisymmetric-mode lamb wave methanol sensor with edge reflectors for fuel cell applications
Author :
Hino, Ryunosuke ; Esashi, Masayoshi ; Tanaka, Shuji
Author_Institution :
Dept. of Nanomech., Tohoku Univ., Sendai, Japan
Abstract :
A Lamb wave sensor to measure the concentration of methanol solution in direct methanol fuel cell (DMFC) systems was designed, fabricated and evaluated. The sensor piezoelectrically generates the lowest antisymmetric mode (A0-mode) Lamb wave on a suspended thin AlN/SiO2/Si composite membrane, and confines a standing wave with edge reflectors. The fabricated sensor showed an almost constant sensitivity of 510 ppm/% in methanol concentration from 0 % to 100 %. The temperature coefficient of frequency (TCF) was found to be -31 ppm/K, which might approach zero by using a 1 ¿m thick buried oxide (BOX) layer.
Keywords :
direct methanol fuel cells; optical elements; surface acoustic wave sensors; AlN-SiO2-Si; BOX layer; DMFC; TCF; antisymmetric-mode lamb wave methanol sensor; buried oxide layer; composite membrane; direct methanol fuel cell; edge reflectors; methanol solution concentration measurement; piezoelectric sensors; sensitivity; temperature coefficient of frequency; Acoustic devices; Acoustic sensors; Acoustic waves; Biomembranes; Fluid flow control; Frequency; Fuel cells; Methanol; Oscillators; Sensor systems and applications;
Conference_Titel :
Micro Electro Mechanical Systems (MEMS), 2010 IEEE 23rd International Conference on
Conference_Location :
Wanchai, Hong Kong
Print_ISBN :
978-1-4244-5761-8
Electronic_ISBN :
1084-6999
DOI :
10.1109/MEMSYS.2010.5442345
