Controlled Bubble Formation From a Microelectrode Single Bubble Generator

In this work, a new micro-electrode bubble generator is presented that employs a micro-electrode installed inside a small nozzle enabling the production of bubbles with controllable size and frequency. This bubble generator can be employed as a simple and potentially cheap method for the generation of single bubbles in a liquid, as long as it enables ion exchange, as an alternative to more complicated methods such as timely injection of a gas through a nozzle, which requires sophisticated nozzle design, manufacturing, and monitoring of the injected gas flow rate. A systematic investigation was conducted to assess the effect of the bubble generator dimensions, applied voltage, and electrolyte flow conditions on the size and frequency of the generated bubbles. It was shown that when the micro-electrode is thinly concealed within the nozzle, this bubble generator can successfully produce bubbles covering a wide range of diameters from 0.4 to 1.4 mm with a size distribution standard deviation of about 25%. The mechanism of single and continuous bubbles formation from the proposed bubble generator is also discussed. While this paper introduces this new micro-electrode bubble generator, further work is required to optimize it, enabling more accurate control over bubble size and frequency.