ACOUSTIC WAVE SENSOR

摘要

Disclosed is an acoustic wave sensor having high sensitivity and good reproducibility. The acoustic wave sensor comprises: (a) a piezoelectric substrate on one major surface side of which a liquid is arranged; (b) a first and second acoustic wave device (10, 20) formed on the major surface of the piezoelectric substrate and respectively having an IDT electrode (11, 21); and (c) a sensitive material which is arranged on a first region of the first acoustic wave device (10) where acoustic waves propagate, and changes in mass loading on the first acoustic wave device (10) due to a substance to be determined that is contained in the liquid.  The liquid arranged on the major surface side of the piezoelectric substrate is agitated by the second acoustic wave device (20), and the frequency detected by the first acoustic wave device (10) changes in accordance with the changes in the mass loading on the first acoustic wave device (10), said changes being caused by the sensitive material.  The second acoustic wave device (20) is formed so that a second region of the second acoustic wave device (20) where acoustic waves propagate is apart from the first region of the first acoustic wave device (10) where acoustic waves propagate.