Recent Progress on Man-Made Inorganic Nanomachines

The successful development of nanoscale machinery, which can operate with high controllability, high precision, long lifetimes, and tunable driving powers, is pivotal for the realization of future intelligent nanorobots, nanofactories, and advanced biomedical devices. However, the development of nanomachines remains one of the most difficult research areas, largely due to the grand challenges in fabrication of devices with complex components and actuation with desired efficiency, precision, lifetime, and/or environmental friendliness. In this work, the cutting‐edge efforts toward fabricating and actuating various types of nanomachines and their applications are reviewed, with a special focus on nanomotors made from inorganic nanoscale building blocks, which are introduced according to the employed actuation mechanism. The unique characteristics and obstacles for each type of nanomachine are discussed, and perspectives and challenges of this exciting field are presented. Micro/nanomachines that can generate controlled mechanical motion from various types of energy sources are essential for future intelligent nanorobotics, nanofactories, and nanobiomedical applications. In this work, state‐of‐the‐art technologies for assembling and actuating micro/nanomachines are reviewed, especially those made from inorganic micro/nanoscale building blocks. The unique working mechanisms, applications, advantages and drawbacks of each type of nanomachine are discussed, as well as the perspectives and challenges of this exciting field.