High-power and time-reversed ultrasound based on FEM simulations and experiments

Time-reversal (TR) is method to focus acoustic energy inside complex media. TR focusing to a predefined target point requires either an echo from a target point with acoustic impedance contrast or direct impulse actuation at the target point. Here, we used FEM to simulate the direct impulse actuation and focused ultrasound successfully to different locations in homogenous media with only four narrowband Langevin transducers. Measured intensities indicate that the focal point of the acoustic field was translated and the pressure scan shows that our TR technique works both in simulation and in experimental domain.