Ionic wind tweezer based on multi-needle corona discharge for programmable droplet manipulation

The manipulation and guidance of tiny droplets are crucial for advancements in fields such as microfluidics, biomedical research, and materials science. In this study, we achieve precise active control of lubricated surface liquid droplets through a multi-needle corona discharge ionic wind tweezer featuring programmed manipulation. The ionic wind tweezer continuously injects charge onto the surface of plate electrodes, causing the oil layer on the electrode surface to form a unique cross-shaped pattern. This pattern confines droplets within the central area of the needle tip, enabling the manipulation of droplets of different compositions, volumes, and arrays. In addition to manipulating water droplets, ionic wind tweezers can also control various solid or liquid particles, revealing the wide applicability and operational capabilities of this method. This work not only provides a flexible strategy for precise droplet manipulation but also sheds light on the application of microfluidics technology in droplet chemical reactions.