Precise and large-scale droplet manipulation base on the stable interface triboelectric transfer

Efficient droplet manipulation is of great significance in both frontier sciences and industrial applications. Although electric-field-driven droplet control enables non-destructive fluid manipulation, greatly expanding the scope and control of microfluidics, droplets are typically electrically neutral, which leads to a great limitation on the direct response to electric fields. In this study, we proposed a novel strategy that integrates self-charged droplets and external electric fields, significantly reducing the driving voltage required for droplet manipulation. A novel separation strategy for the micro-droplets is introduced to enhance electro-driven applications, ensuring the stable and precise droplet motion under various electric fields. We demonstrated that electrospinning technology, when used to fabricate polytetrafluoroethylene (PTFE) films with nanofiber and agglomerate structures on the conductive glass substrates, realizes the flexible and stable droplet control. The particular film not only reduces the droplet’s viscosity but also efficiently charges droplets. As a consequence, the droplets with volumes ranging from 68.5 µL to 87.0 µL can be manipulated stably for effective locomotion of over 5 mm under the 60 V/mm electric field. Moreover, the motion range can be adjusted by external electric field. This integrated strategy provides a reliable and versatile solution for droplet manipulation, with promising applications in the controllable chemical reactions and liquid micro-reactors.