Patent ID: 8486199

Claim:
A device for treating a surface of an article with a fluid, comprising: a holder configured to position an article in a predetermined orientation; a source of ultrasonic or megasonic energy positioned so as to vibrate a fluid medium adjacent the article; wherein said source of ultrasonic or megasonic energy comprises a resonator body having a flat face confronting said holder and contacting said fluid medium, and wherein the resonator body comprises an internal refraction surface at an interface between two materials of the resonator body which differ from one another in at least one acoustic property; wherein said interface comprises a repeating pattern of three-dimensional shapes; and wherein the acoustic properties of the two materials and a shape of the internal refraction surface at the interface are selected such that transmitted sound beams are emitted from the flat face of the resonator body at emitting angles between −90 and +90 degrees to create an interference pattern in the fluid medium comprising regions of pressure amplitude minima and maxima at an interface of the fluid medium and the article.