Ultrasonic/sonic jackhammer

An apparatus that combines power from multiple piezoelectric transducer units into a single impactor for breaking a hard surface on a target, comprising:

• a piezoelectric actuator configured to generate vibrations only in the axial direction of the actuator and directly from electric input at a resonance frequency, the piezoelectric actuator comprising a plurality of separate units, each unit comprising a piezoelectric stack compressed between a backing and a horn, wherein all the units are of substantially identical length and are arranged in a lateral dimension, their horns angled with respect to each other so as to converge, causing their power to combine when each of the plurality of units are driven to vibrate at substantially the same frequency;
• and
• a solid chisel-like impactor, with at least two opposing sides tapering toward and terminating at a distal linear edge, and configured to be displaced by the axial vibrations generated by the piezoelectric actuator for causing structural breakage in a target, wherein the impactor is rigidly connected to the actuator through the horns of the piezoelectric units such that the impactor vibrates at substantially the same resonance frequency as the actuator.