Figure 3.

Acoustic focusing based on the light addressed microbubble generation. a) The microbubble pattern generated on the silicon surface. The images were obtained by subtracting the photo with that before illumination. The scale bar is 10 mm. The projected light patterns are in the upper left insets. The microbubble generation process is shown in Video S2 in the Supporting Information. b) The calculated acoustic field at the target focus plane (80 mm away from the silicon wafer surface). c) The experimental results reveal the microbubble pattern modulates the acoustic waves into target foci. The scale bar is 2 mm in (b) and (c).