Electrostatic tweezer for droplet manipulation

Significance The manipulation of liquid droplets plays a crucial role in multidisciplinary applications. However, existing methods still face many challenges, such as short distance, low velocity, restricted operating conditions, the need for extra responsive additives in droplet, and so on. To circumvent these constraints, here we develop a droplet electrostatic tweezer to trap the liquid droplet or faithfully guide the droplet motion in a remote manner. Our method allows high flexibility and precision in manipulating droplets of different types, volumes, and numbers under different working conditions, such as in open and closed spaces and on flat and tilted surfaces as well as in oil medium, imparting various applications, such as high-throughput and high-sensitivity Raman detection.