Downhole piezoelectric acoustic transducer

A sensor system for use in a wellbore, the sensor system comprising:

• a piezoelectric transducer for generating an acoustic wave in a fluid medium of the wellbore by repeatedly bending between two positions in response to an actuation signal, the piezoelectric transducer comprising exactly four piezoelectric layers stacked on top of one another, each layer of the four piezoelectric layers coupled to an adjacent layer via a bonding material and comprising:
• a piezoelectric material,
• a top electrode coupled to a top surface of the piezoelectric material, and
• a bottom electrode coupled to a bottom surface of the piezoelectric material;
• wherein a middle two of the four piezoelectric layers are polarized in one direction and an outer two of the four piezoelectric layers are polarized in an opposite direction;
• and
• a hydrophone for detecting a reflection or a refraction of the acoustic wave off an object in the wellbore and transmitting an associated signal to a processing device.