An ultrasonic transducer device for use in an acoustic biometric imaging system, the ultrasonic transducer device comprising: a first piezoelectric element having a first face, a second face opposite the first face, and side edges extending between the first face and the second face; a first transducer electrode on the first face of the first piezoelectric element; a second transducer electrode on the second face of the first piezoelectric element; and a spacer structure leaving at least a portion of the first transducer electrode of the first piezoelectric element uncovered.