Ultrasonic homogenizers, commonly referred to as “sonicators,” disrupt tissues and cells through cavitation and ultrasonic waves. Basically, an ultrasonic homogenizer has a tip which very rapidly vibrates, causing bubbles in the surrounding solution to rapidly form and collapse. This creates shear and shock waves which tear apart cells and particles.
Ultrasonics / sonicators are great for breaking apart cells and subcellular structures in suspension. They are not good for homogenizing intact tissue. Ultrasonic homogenizers can also shear DNA, which could be a good thing or a bad thing depending on your application. Other applications include creating emulsions, dispersing nanoparticles, and reducing the size of particles in suspension. Sonicators generate a significant amount of heat so they may not work well with temperature-sensitive samples. Acoustic enclosures are highly recommended; after all, you’re homogenizing using high-powered sound waves.