Pressure waves have the potential to cause injury to cells and tissue or enable novel therapeutic modalities, such as fragmentation of kidney stones and drug delivery. Research on the biological effects of pressure waves have shown that the biological response on depends the pressure‐wave characteristics. One of the most prominent effects induced by pressure waves is the permeabilization of a number of barrier structures (cell plasma membrane, skin and microbial biofilms) and facilitate the delivery of macromolecules. The permeabilization of the barrier structure is transient and the barrier function recovers. Thus, pressure waves can induce delivery of molecular species that would not normally cross the barrier structure. © 2004 American Institute of Physics