Ball SAW(surface acoustic wave) device was fabricated on a spherical φ 1 mm single crystal quartz. On Z-axis cylinder, it has multiple roundtrips of more than 190 turns and a long propagation length of 157[mm] at 150[MHz] of driving frequency and 50th turns roundtrip. Using this device, we realized a hydrogen gas sensor as an application of Ball SAW device. Amplitude and delay time responses were measured under exposure to 10ppm to 3% H2 in N2 base gas by using a selective sensing film of 40nm thick Pd/Ni alloy. The response time was about 30 sec in 3% H2.
ASJC Scopus subject areas
- Acoustics and Ultrasonics