Purely viscous acoustic propulsion of bimetallic rods

A Practical Guide to Analyzing and Reporting the Movement of Nanoscale Swimmers

“…For externally powered nanoswimmers, identifying the mechanism is often more straightforward than for their chemical counterparts. Typically, a magnetically powered nanoswimmer twists its body or rolls on a surface in a rotating magnetic field; − an electrically powered Janus nanoswimmer moves on a 2D plane sandwiched between two conductive electrodes by a mechanism known as induced charge electrophoresis (ICEP); and an acoustically powered nanorod moves in a levitation plane created by resonating ultrasonic waves, , or by resonant oscillation of an on-board bubble. , There are certainly variations and caveats to each of these mechanisms, but, in general, there is some consensus as to how they work.…”

Acoustic Propulsion of Nano- and Microcones: Dependence on the Viscosity of the Surrounding Fluid

“…After the idea of nano- and micromachines that carry out medical tasks inside a patient’s body has been a dream for several decades, the progress in nanotechnology at the end of the last century made the fabrication of motile nano- and microparticles (so-called active particles) possible. − During the last two decades, a large number of artificial motile nano- and microparticles that utilize various mechanisms for propulsion have been developed, ,− and fascinating future applications of these particles have been envisaged in fields like medicine, − where they could be used for targeted drug delivery, − materials science, − where they could be used to form active crystals − and other new types of matter, and environmental care. ,− …”

“…Among all propulsion mechanisms that have been developed so far, acoustic propulsion, − ,− ,− ,− ,− ,− where nano- or microparticles in a fluid become motile when they are exposed to an ultrasound wave, is one of the most promising mechanisms. ,,,,− Important advantages of this mechanism compared to other ones are its biocompatibility, , its compatibility with various types of fluids, ,,,,,,,,,,,, and an easy way of permanently supplying particles with energy. , For special purposes, acoustic propulsion can even be combined with other propulsion mechanisms. ,,,,,, …”

“…Despite intensive research on acoustically propelled nano- and microparticles based on experiments, − ,− computer simulations, ,,,,− and analytical approaches, , this is still a rapidly growing field of research with many important questions remaining unanswered. For example, little is known about how the propulsion of such a particle depends on the viscosity of the surrounding fluid.…”

Navigation of Ultrasound-controlled Swarmbots under Physiological Flow Conditions

“…More importantly, ultrasound imaging systems are already widely used in clinical settings for the real-time imaging of objects, and such systems have recently been utilized for tracking microrobots (27,35,36). Ultrasound-based microrobots are gradually becoming popular because the designs are relatively simple, their fabrication is inexpensive and does not require doping with magnetic particles, their experimental setup is likewise inexpensive, and their operation is simple (37)(38)(39)(40)(41). Resonating microbubbles confined in soft microfabricated shells that are capable of extremely fast and selective micro-propulsion have been utilized in 3D manipulation (42)(43)(44).…”