Ultrasonic cleaning has been used industrially for decades,[when?] particularly to clean complex shape parts and/ or having small intricate holes/galleries, and to accelerate surface treatment processes.[3]
It appears that ultrasonic cleaners developed as a natural evolution of several earlier inventions that used vibrations to agitate and mix substances, and thus there is no clear "inventor" of ultrasonic cleaning. US patent 2815193, issued December 1954, is the earliest patent on record that specifically uses the term "Ultrasonic cleaning" although earlier patents refer to the use of ultrasound for "intense agitation," "treatment" and "polishing," e.g. US 2651148.
By the mid-1950s there were at least three ultrasonic cleaner manufacturers established in the United States and two in the United Kingdom; and by the 1970s ultrasonic cleaners were widely established for industrial and domestic use.[4][5]