CYLINDRICAL ULTRASOUND RECEIVERS AND TRANSCEIVERS FORMED FROM PIEZOELECTRIC FILM

摘要

An ultrasound receiver (20) includes a hollow cylinder (22) formed primarily from flexible piezoelectric film, the hollow cylinder (22) having an outer surface (24) an inner surface (26), a central axis (28) and a height measure d parallel to the central axis (28). A sensing electrode is formed from conductive material applied to the surface, while a grounded electrode (32) is formed from conductive material applied to the outer surface (24). The hollo w cylinder (2) is supported by a support structure configured to allow propagation of vibration waves circumferentially around a major part of the hollow cylinder (22). The sensing electrode is formed as a strip extending i n an extensional direction substantially parallel to the central axis (28) alo ng a major part of the height, the strip subtending at the central axis (28) at an angle of not more than 90 degrees.