A monolithic ultrasound fingerprint sensor has been developed, utilizing advanced technologies such as optomechanical ultrasonic sensors and piezoelectric micromachined ultrasound transducers. The sensor's capabilities are being explored in various applications, including high frame rate ultrasonic flowmeters and in vivo photoacoustic imaging. Research on the sensor's design and functionality is ongoing, with studies focusing on its sensitivity, miniaturization, and integration with other technologies.