TY - JOUR
T1 - Principle and application of ball surface acoustic wave (SAW) sensor
AU - Yamanaka, Kazushi
AU - Nakaso, Noritaka
AU - Sim, Dongyoun
AU - Fukiura, Takeshi
PY - 2009
Y1 - 2009
N2 - Detection of hydrogen gas is a crucial task for establishing safety and reliability of fuel cells, a key technology for the environment and our society. However, hydrogen is difficult to detect and various hydrogen sensors have many drawbacks. Here we report a novel hydrogen gas sensor, the ball surface acoustic wave (SAW) sensor, using Pd or PdNi sensitive film. The ball SAW sensor is based on a novel phenomenon, diffraction-free propagation of collimated beam along an equator of sphere. The resultant ultra-multiple roundtrips of SAW makes it possible to achieve highest sensitivity among SAW sensors. Moreover, it enables to use a very thin sensitive film, and consequently the shortest response time (2 s) was realized. In terms of the sensing range, it has the widest range of 10 ppm to 100% among any hydrogen sensors including FET or resistivity sensors. The response time was less than 1 s for 3.0% hydrogen concentration in nitrogen gas, evaluated by using a newly developed digital quadrature detector.
AB - Detection of hydrogen gas is a crucial task for establishing safety and reliability of fuel cells, a key technology for the environment and our society. However, hydrogen is difficult to detect and various hydrogen sensors have many drawbacks. Here we report a novel hydrogen gas sensor, the ball surface acoustic wave (SAW) sensor, using Pd or PdNi sensitive film. The ball SAW sensor is based on a novel phenomenon, diffraction-free propagation of collimated beam along an equator of sphere. The resultant ultra-multiple roundtrips of SAW makes it possible to achieve highest sensitivity among SAW sensors. Moreover, it enables to use a very thin sensitive film, and consequently the shortest response time (2 s) was realized. In terms of the sensing range, it has the widest range of 10 ppm to 100% among any hydrogen sensors including FET or resistivity sensors. The response time was less than 1 s for 3.0% hydrogen concentration in nitrogen gas, evaluated by using a newly developed digital quadrature detector.
KW - Bearing ball
KW - Gas sensor
KW - Hydrogen
KW - Multiple roundtrip
KW - Naturally collimated beam
KW - Surface acoustic wave
UR - http://www.scopus.com/inward/record.url?scp=58449131942&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=58449131942&partnerID=8YFLogxK
U2 - 10.1250/ast.30.2
DO - 10.1250/ast.30.2
M3 - Article
AN - SCOPUS:58449131942
VL - 30
SP - 2
EP - 6
JO - Journal of the Acoustical Society of Japan (E) (English translation of Nippon Onkyo Gakkaishi)
JF - Journal of the Acoustical Society of Japan (E) (English translation of Nippon Onkyo Gakkaishi)
SN - 1346-3969
IS - 1
ER -