A 10 mm Aperature 8-Element Annular Array Histotripsy Transducer

A 10 mm diameter annular array histotripsy transducer was fabricated and tested. The transducer was based on a PZ39 substrate bonded to a focused aluminum lens with an f-number of 0.7. The device produced a much higher pressure (0.52 MPa/V) than the previously presented 10 mm diameter device (0.29 MPa/V). The addition of the laser cut 8-element array allowed to focus to be steered over a range of 2 mm. This was tested on an anesthetized rat to produce an approximately 3 mm long by 0.5 mm brain ablation. The focus was quickly steered over the 2 mm range with a period of 80 ms. This was evaluated on a gelatin tissue phantom demonstrating the potential of the annular array design for rapid volume ablations.