Mass sensitivity of thin rod acoustic wave sensors

摘要

Theoretical and experimental investigations of mass sensitivitiesnof thin rod acoustic wave sensor are presented. From the low-frequencynapproximation of the dispersion equations, explicit forms of thenrelation describing the mass sensitivity are derived with thenconsideration of the effects due to elasticity and inertia of thenloading layer. The three lowest thin rod acoustic modes are presented.nMass sensing experiments are based on the electrodeposition of loadingnmaterial on a thin metallic fiber (the thin rod). Copper has been usednto load the propagation of acoustic waves in gold fibers. The mass ofncopper deposited and the phase shift of the acoustical thin rod delaynline were monitored simultaneously by a computer. Mass response curvesnshowing the variation in phase due to the mass deposited per unitnsurface area were then obtained in order to determine the massnsensitivity. Both flexural and extensional wave modes have been excited.nTheoretical and experimental results were found to be consistent in bothnsign and magnitude