Programmable Triboelectric Wetting Interface for Multifunctional Droplet Manipulation on Tracks

Abstract

Precise and multifunctional droplet manipulation has attracted increasing interest in fields such as biochemical analysis, microfluidics, and energy harvesting. Nonetheless, triboelectric droplet actuation remains constrained in multidimensional configurations due to limited surface charge retention. In this study, a flexible triboelectric wetting interface with a track-guided design is developed to enable non-contact droplet manipulation on curved, vertical, and geometrically complex surfaces. By integrating a heterogeneous substrate with a multilayered architecture, the interface produces a surface potential difference of ≈2.4 kV, enabling directional droplet transport against gravity. Additionally, the system facilitates controlled droplet motion across gaps of up to 10 mm and allows the manipulation of droplets with volumes up to 1.8 mL. This work advances the understanding of structure–function relationships in multicomponent liquid–solid contact electrification and wetting modulation, offering a scalable and adaptable platform for precise and versatile droplet operations.