Ultrathin ultrasonic transducer array

An ultrathin ultrasound device, comprising:

• an ultrasonic transducer array that includes a plurality of elements each comprising a back electrode and a front electrode, and each configured to:
• generate ultrasound waves for launching from a front surface into a region of a subject, and
• receive echoes from the region in response to the ultrasound waves being launched from the front surface, the front surface encompassing the front electrode;
• a backing layer positioned at a back surface of the ultrasonic transducer array and configured to absorb the ultrasound waves generated by the ultrasonic transducer array that otherwise would be launched from the back surface, the back surface encompassing the back electrode;
• and
• a flexible printed circuit board (FPCB) electrically connected to the front electrode and the back electrode of each of the plurality of elements of the ultrasonic transducer array so that the plurality of elements can generate the ultrasound waves when driven by electrical pulses and generate electrical signals when the echoes are received,
• wherein the ultrathin ultrasound device is sized at five millimeters or less in thickness.