Hybrid Photovoltaic 2D/3D Self‐Propulsion of Aqueous Microdroplets with Light‐Sensitive Cargos Achieved by Nonlocal Laser‐Scanning on Superhydrophobic LiNbO 3 :Fe Surface with a High Triboelectricity

Abstract Achieving 2D/3D self‐propulsion of aqueous microdroplet with light‐sensitive cargos presents a big challenge. Here, on a superhydrophobic LiNbO 3 :Fe surface with a high triboelectricity, a rocking‐assisted charging mode of aqueous microdroplets, is demonstrated namely charging through the microdroplet rocking that is induced by the oscillation of photovoltaic interaction generated by nonlocal toroidal laser‐scanning, for manipulating the microdroplets in a hybrid photovoltaic way. It enables a stationary aqueous microdroplet to acquire sufficient charges for the self‐propulsion toward a direction controlled by the notch of toroidal laser‐scanning path, without being illuminated directly by laser. The dynamic analysis of the self‐propulsion process, along with the numerical simulation of the photovoltaic field induced by the laser‐scanning, reveals that the triboelectric charges of 10 −11 –10 −10 C accumulate in the rocking microdroplet and that, the repulsive coulomb force induced by the patterned photovoltaic field locks the motion direction of the microdroplet and drives it away from the laser‐scanning area. In particular, this strong coulomb repulsion allows microdroplets to safely transport light‐sensitive cargos such as photobleachable fluorescent dyes and fragile Euglena viridis on the substrate (2D) or through free space (3D) with the jumping angle controlled by the laser‐scanning speed at the notch part.