Thin-film ultrasonic probe having a flexible membrane

A method for examining an item using an ultrasonic probe including a body having a contact surface and a fluid channel extending between a fluid inlet and a fluid outlet in the contact surface, a spacer including delay fluid disposed in a chamber of the body and a membrane adjacent said contact surface sealing said delay fluid inside the chamber and forming a coupling surface, and an ultrasonic transducer connected to the body adjacent said spacer, the method comprising:

• positioning the contact surface of the probe body in contact with a contact surface of the item;
• delivering coupling fluid to the coupling surface of said spacer by way of said fluid channel to form a film of the coupling fluid on the coupling surface;
• producing ultrasonic signals using said transducer;
• propagating said signals through the spacer and to the item;
• moving the probe along the contact surface of the item;
• and
• determining characteristics of the item based on ultrasonic signals reflected from the item back to the transducer.