Characterization of Stable and Transient Cavitation in a Dual-Frequency Acoustic Field Using a Hydrophone

Sonication is a commonly used method for particle removal from various surfaces. There has been a growing interest in the use of combination of two or more acoustic frequencies for cleaning as it is expected to achieve better particle removal efficiency and lower feature damage compared to a single frequency acoustic system. In this study, stable and transient cavitation characteristics in de-ionized water subjected to dual-frequency irradiation have been illustrated using experimentally obtained absolute values of cavitation pressures and pressure-frequency spectra. Comparison of the calculated ratio of stable cavitation pressure to transient cavitation pressure suggests that dual-frequency mode has the potential to reduce feature damage while maintaining the particle removal efficiency compared to low frequency ultrasonic field. These observations are further confirmed from the results of damage studies conducted on aluminum coated glass samples.