Recent trends in bulk acoustic wave resonator sensors

Devices based on piezoelectric materials, which allow transduction between electrical and acoustic energies, have been developed in a number of configurations for sensor applications and materials characterization. Bulk acoustic wave resonators like QCM and ultrasonic sensors can be classified in the category of acoustic wave resonators sensors. The latter will not be considered here. In the following the state-of-the-art of bulk acoustic wave resonator sensors will be discussed. Models for the description of the transduction mechanisms of acoustic-wave based chemical or biochemical sensors are introduced and compared to derive the application chance and limitations of these sensors. The importance of suitable sensor interface electronics for getting exact sensor data in damping fluid systems will be shown. In this context the signal-to-noise-ratio (SNR) plays a dominant role. Selected application examples are given. Aspects of future trends are discussed.