Which parameters affect biofilm removal with acoustic cavitation? a review

Bacterial biofilms are a cause of contamination in a wide range of medical and biological areas. Ultrasound is a mechanical energy that can remove these biofilms using cavitation and acoustic streaming, which generates shear forces to disrupt biofilm from its surface. The aim of this narrative review is to investigate the literature on the mechanical removal of biofilm using acoustic cavitation to identify the different operating parameters affecting its removal using this method. The properties of the liquid and the properties of the ultrasound have a large impact on the type of cavitation generated. These include gas content, temperature, surface tension, frequency of ultrasound and acoustic pressure. Many of these parameters require more research to understand their mechanisms in the area of ultrasonic biofilm removal and further research will help to optimise this method for effective removal of biofilms from different surfaces.