Ultrasonic Cleaning Technology for Infection Control: What is it?

Ultrasonic cleaning is an effective technology routinely used in health care facilities worldwide to clean surgical and dental instruments prior to sterilization. The primary physical phenomenon of ultrasonic cleaning is cavitation, - cavitation is a by-product of transmitting high frequency sound waves into a liquid medium and is one of natures most efficient amplifiers of energy density known to man.

Alternating phases of rarefaction and compression during sound wave transmission into a liquid will produce and subsequently collapse millions of microscopic vacuum cavities each second. The collapse or implosion of these cavities cause high powered micro-jets of liquid to be propelled throughout the bath removing even the most tenacious particles upon impact. The rate at which these cavities form and implode, as well as the intensity of the implosions are proportional to the frequency that is being transmitted. During the rarefaction or minimal pressure phase of sound wave transmission the liquid is stretched beyond its tensile strength whereby millions of microscopic vacuum cavities form. These cavities form and build to tremendous temperatures and pressures - then upon the compression phase of the sound transmission the cavities are compressed beyond their elastic threshold until they collapse or implode. The implosions radiate shock waves that drive the liquid violently creating micro-jets of effluent to blast throughout the bath.

Each collapse is accompanied by the generation of temperatures of several thousand degrees centigrade and pressures greater than hundreds of atmospheres.

The key factor in cleaning effectiveness of an ultrasonic system is cavitation. The greater the cavitation intensity of the liquid - the better the cleaning results will be.