Nanomotors driven by waves with different frequencies

A diverse range of light and waves, spanning from near-infrared to ultraviolet, alongside ultrasound, have proven effective in propelling nanomotors. This review encapsulates the advancements in nanomotor research propelled by waves of varying frequencies. It delves into the driving mechanisms and control methodologies of different nanomotor types, emphasizing the role of frequency. Nanomotors can be classified based on the frequency of the driving wave, encompassing ultraviolet light-driven, visible light-driven, near-infrared-driven, and ultrasound-driven variants. Each category corresponds to distinct propulsion mechanisms, including momentum transfer, photothermal effects, self-electrophoresis, and acoustic radiation force. Notably, visible light and near-infrared radiation predominantly propel momentum transfer nanomotors, while photothermal nanomotors are chiefly active within the infrared spectrum. Ultraviolet light drives most self-electrophoretic nanomotors, while ultrasound-driven nanomotors respond to acoustic radiation force. Furthermore, precise control over nanomotor speed and direction is achievable by adjusting the frequency of incident waves within a narrow range, modulating wave absorption rates. Lastly, this paper explores microwave nanomotors, an area yet to be reported, shedding light on potential driving mechanisms.