Progress on the fabrication strategies of self-propelled micro/nanomotors

Artificial micro/nanomotors (MNMs) with self-propelled motion behavior by utilizing chemical or external energies have attracted increasing research interests in various fields. In the past decades, scientists from multidiscipline took advantage of both bottom-up and top-down approaches to develop MNMs with various geometrical shapes, such as tubular, spherical, helical, and other irregular shapes. However, it has always been a considerable challenge to efficiently synthesize MNMs with large-scale at a low cost, which greatly impacts the practical applications of MNMs. In this review, we focus on various techniques/strategies for the fabrication of MNMs and their own advantages and limitations are discussed as well.