Description of ultrasound transducers through wave parameters

Abstract

High energy ultrasonic waves cause cavitation in liquids. Since many years, a great number of low frequency cavitation effects is well known such as ultrasonic cleaning and biological cell disruption. Recently the interest in high frequency applications has been rising considerably, e.g. in the formation of peroxide in destilled water or the cleaning of wafers. These and other applications require efficient and reliable high frequency transducers. Therefore we are working on the design and optimization of transducers with frequencies of about 100 kHz up to 3 MHz. According to the specific demands of this process, computer simulations are being used in the course of the optimization. The Finite Elements Method, for example, is applied to investigate the forms of vibration. In addition to this, Network Analysis Methods are used to optimize the power transformation and the band width. By these means an average efficiency of about 80 percent is reached. These transducers are developed for laboratories as well as for technical scale applications.