In this paper new observations of a laser-generated cavitation bubble interacting with an inertial boundary are presented. Employing schlieren photography techniques and a thin film transducer placed on the surface of the boundary, the pressure stresses induced in the solid boundary and the surrounding fluid by collapsing bubbles, created very close to the solid surface, are experimentally measured. Liquid jet development, shock wave emission, and "splash" phenomena are identified. For different creation sites close to the boundary, the relevance of each of these phenomena with respect to potentially damaging pressure stresses in the boundary is speculated on.

In this paper we present new observations of a laser generated cavitation bubble interacting with an inertial boundary. Employing schlieren photography and Mach–Zehnder interferometry techniques, we present photographic sequences of a cavity interacting with a flexible membrane. During expansion the membrane is deformed away from the bubble centroid but during the collapse phase, instead of moving with the expected fluid motion caused by the contracting bubble, the flexible membrane introduces a certain asymmetry into the problem which in turn results in novel fluid motions around the bubble.

In this work we consider the interaction of a laser-generated cavitation bubble with a solid boundary for the case of a cavity created very close to the wall. Using a combination of a thin-film transducer placed on the surface of the boundary and schlieren photography techniques we observe the induced pressure stresses on the solid boundary and in the surrounding fluid. By studying bubble shapes and identifying the formation of a liquid jet and shock wave emission, we speculate on the dominant pressures stresses induced by the bubble around the time of its first minimum volume for this chosen creation site of the cavity.

A technique for producing strong focused negative pressure waves in water is described. The method is based on the phase inversion of the planar shock wave from an electromagnetic transducer. This is achieved by reflection and focusing at a pressure release boundary. The acoustic concentrator has a phase inverting central element and a phase maintaining annular mirror. Focal pressures of approximately −16 MPa from an initial + 5 MPa EMAT source have been measured and the focal volume was found to be approximately the same as that obtained with a conventional ultrasonic lens. The electromagnetic transducer and the parabolic concentrator is an excellent source of cavitation bubbles in water. The focused negative wave has been observed using high speed laser-lit Schlieren photography.