Micro-/Nanomachines Driven by Ultrasonic Power Sources.

Autonomous micro-/nanomachines that can convert diverse energy sources into effective locomotion under the constraint of low Reynolds numbers hold considerable promise for a variety of applications, such as cargo delivery, localized biosensing, nanosurgery, and detoxification. In this Minireview, we briefly overview recent advances in the development of micro-/nanomachines that are specifically powered by ultrasound, in particular new concept design, their working principles, and their fabrication and manipulation strategies. Finally, the exclusive biocompatibility and sustainability of ultrasound-powered micro-/nanomachines, as well as the critical challenges that face their in vivo application, are discussed to provide insight for the next phase of micro-/nanomachines with versatile functionalities and enhanced capabilities.