Inhibition of Biofilm Growth in Microchannels via Alternating Electric Fields with embedded 3D microelectrodes

Biofi lms in microchannels are a key area of research in microbiology, biomedical engineering, and microfl uidics. Microchannels provide an ideal environment for biofi lm formation due to their high surface-area-to-volume ratio and controlled fl uid dynamics. Understanding biofi lm behaviour in these systems is crucial for applications such as lab-on-a-chip devices, biofouling prevention, and microreactors. In this study, we fabricated a microfl uidic device using photolithography. The cured PDMS layer was bonded to a glass slide via oxygen plasma treatment, which also made the channel walls hydrophilic. The device included a primary channel for biological samples and two side electrode channels forming a 3D integrated electrode system to apply an alternating electric fi eld. A Pseudomonas fl uorescens bacterial suspension was introduced at 0.1 µL/min, allowing biofi lm formation over 48 hours. The biofi lm developed on both sides of the main channel. To investigate electric fi eld eff ects, voltages from 5 Vpp to 20 Vpp were applie d at 1 MHz for diff erent durations. The frequency was also varied from 1 MHz to 20 MHz at a constant voltage of 10 Vpp. The electrode channels, separated from the main channel by a 10 µm PDMS structure, enabled close- fi eld exposure. Disrupted biofi lms were removed using fl ow rates from 1 to 10 µL/min. This study optimizes electric fi eld parameters for biofi lm disruption in microchannels, providing a non-invasive approach for biofi lm management with potential biomedical, industrial, and environmental applications.