When was the last time you had to roll up your sleeves, soap up a rag, and wash a nice sink-load of dirty dishes? I’m guessing last night, unless you’re a bachelor. In that case, it’s better if you don’t answer. Well, in the 1950s folks got pretty sick of washing dishes and laboratory equipment the same old way it had always been done. And no, I’m not referring to the advent of the automatic dishwasher. I’m referring to ultrasonic cleaners! Although they didn’t see home use until around the 1970s, ultrasonic cleaning was used extensively in industrial application after its discovery. Utilizing sound waves, the device emits variable, oscillating frequencies of ultrasonic waves into fluid within a container. By emitting the sound waves into liquid, they can travel throughout the container and disperse their energy to any particles submerged within. In the case of a dirty beaker, these sonic waves will bounce off of the beaker and the contaminants on top of it, effectively loosening and removing them in the process. This is thanks to a phenomenon known as ‘cavitation’, in which the ultrasonic waves exert pressure within the liquid and create bubbles, or voids, transferring their force onto any contaminants they come into contact with. Through this action, ultrasonic waves ‘clean’ the contents of the device.
Since sound waves bounce, or refract, off of surfaces, ultrasonic cleaners are perfect for applications requiring detailed and impeccable cleaning. Ideal materials that are easily cleaned ultrasonically include glass, aluminum, ceramic, and rubber. Essentially, most non-volatile solids are perfect candidates. Due to the fine, deep cleaning of ultrasonic waves, often they are used in laboratory environments requiring clean materials and contaminant-free tools. One such brand that sees widespread use in the medical field are Branson ultrasonic cleaners, which work the same way as the larger, industrial models. Much smaller, they usually are sized to fit on any standard lab bench and can either use tap water, deionized water, or specialized cleaning solutions as the liquid medium. However, as is important to remember, ultrasonic cleaners do not sterilize the instruments placed within—they only remove debris and contaminants, so sterilization is still a necessary step after ultrasonic cleaning.
Branson ultrasonic cleaners offer a slew of special features that were previously unavailable or prohibitively expensive, such as sweep frequency oscillation to prevent vibration from moving the machine around the lab bench and a number of fitted accessories that fit within the tank during cleaning. For different applications, different cleaning solutions may be more suitable.