Acoustic propulsion of nanomachines depends on their orientation

Microscopically tiny nanomachines which move like submarines with their own propulsion—for example in the human body, where they transport active agents and release them at a target: What sounds like science fiction has, over the past 20 years, become an ever more rapidly growing field of research. However, most of the particles developed so far only function in the laboratory. Propulsion, for example, is a hurdle. Some particles have to be supplied with energy in the form of light, others use chemical propulsions which release toxic substances. Neither of these can be considered for any application in the body. A solution to the problem could be acoustically propelled particles. Johannes Voß and Prof. Raphael Wittkowski from the Institute of Theoretical Physics and the Center for Soft Nanoscience at the University of Münster (Germany) have now found answers to central questions which had previously stood in the way of applying acoustic propulsion. The results have been published in the journal ACS Nano.