Jet Flow Focusing-Assisted Damage-Free Cleaning of Microstructures by Acoustically Oscillating Bubbles in a Commercial Fluoropolymer Tube Array

Abstract

It is critical to effectively clean contaminated microstructured surfaces without damaging their structure in various applications such as semiconductor manufacturing, additive manufacturing, and filtration membranes. To this end, we proposed a cleaning device that uses a focused jet stream generated by oscillating bubbles inside a commercially available fluoropolymer tube array to effectively remove nanoparticle contamination from microstructures. The natural hydrophobicity of the fluoropolymer tube and the 3D-printed frame for mounting the tubes provided convenience and flexibility in the design and development of the device. To design our cleaning device, we thoroughly investigated the jet flow characteristics caused by the oscillation of individual bubbles trapped in a fluoropolymer tube and the physical factors influencing them, such as the applied voltage, frequency, tube dimensions, and inclination. Based on these findings, we created a cleaning device with a central vertically oriented tube and nine inclined tubes with the assistance of 3D printing. We also fabricated a portable cleaning device to improve the usability and adaptability of the proposed cleaning device. Finally, the cleaning efficiency of the proposed cleaning device was compared with that of an ultrasonic cleaner, demonstrating the feasibility of targeted cleaning without physical damage to the microstructures.