Controllable Droplet Splitting with Parallel-Plate Optoelectrowetting Chips.

Recent advances in microfluidic technology highlight electrowetting for its programmability and precision. However, traditional electrowetting chips face limitations in scalability due to fixed electrode sizes. Optoelectrowetting (OEW) offers a solution with light-controlled virtual electrodes, but droplet splitting remains challenging. This study introduces a parallel-plate OEW chip, enhancing droplet manipulation and achieving rapid splitting with light-controlled dark stripe electrodes. We proposed the dimensionless parameter to characterize droplet splitting, and a mathematical model describes key factors influencing controllable splitting, providing valuable design guidelines for OEW chips.