Inspired by natural ciliary movement, artificial cilia systems have recently been developed to transport microparticles and target biomolecules by the external stimuli-induced bend and twist. However, the directional transportation of cargo meets a major challenge. Here, we present an artificial asymmetric cilia array of dielectric elastomer and realize the cargo directional transportation under alternating-current (ac) electric field. Such a dielectric elastomer is composed of elastomer matrix and dielectric barium titanate (BaTiO3) nanoparticles, which can be polarized under an ac electric field and results in the swinging of artificial elastomer cilia. The asymmetry of the cilia endows themselves with the capability of asymmetric recovery stroke, which is essential for directional transportation of cargo. Transporting performance is also optimized by adjusting the applied frequencies and voltages. This study may provide a new clue to construct functional "smart" devices in electromechanical systems and biomedicine.
Keywords: artificial; asymmetric; cargo transportation; cilia array; dielectric elastomer.