Ultrasonic-assisted extractions can recover oils from microalgae cells through cavitation (Harun et al., 2010). During the low-pressure cycle, high-intensity small vacuum bubbles are created in the liquid. When the bubbles attain a certain size, they collapse violently during a high-pressure cycle. During the implosion very high pressures and high-speed liquid jets are produced locally, and the resulting shear forces break the cell structure mechanically. This effect supports the extraction of lipids from algae (Wei et al., 2008). The high-pressure cycles of the ultrasonic waves support the diffusion of solvents, such as hexane, into the cell structure. As ultrasound breaks the cell wall mechanically by the cavitation shear forces, it facilitates the transfer of lipids from the cell into the solvent (Cravotto et al., 2008).