Material selection, preparation, driving and applications of light-driven micro-nano motor: a review

Abstract

As an external energy stimulus, light possesses the advantageous qualities of being reversible, wireless and remotely maneuverable, while driving the motion of the micro and nano motors. Despite the extensive publication of articles on light-driven micro- and nano-motors (LDMNMs) over the past two decades, a review that addresses LDMNMs in general, from material selection, design, preparation, driving to applications, remains scarce. Therefore, it is necessary to highlight the superiority of light as a stimulating energy source for driving MNMs, as well as to promote the continuous development of LDMNMs and give newcomers a more basic and comprehensive knowledge in this field. This present review focuses on advanced preparation methods for LDNMNs, and provides a comprehensive comparison of the advantages and limitations of various techniques. In addition, general design strategies for building asymmetric fields around LDMNMs are introduced, as well as a variety of photoactive materials, including photocatalytic, photothermal, and photoinduced isomerization materials. The following section will describe in detail the existing propulsive mechanisms and kinematic behaviours of LDMNMs, involving photocatalytic oxidation, photothermal effects and photo-induced isomerization. The principles of the various drive mechanisms are also analysed in detail and their merits and shortcomings summarized. Finally, following a comprehensive review of the potential applications in biomedicine, environmental remediation and other fields, further perspectives on future developments are presented with a view to overcoming key challenges