Micromotors are propelled by a variety of chemical reactions, with most of them being of catalytic nature. There are, however, systems based on redox reactions, which show clear benefits for efficiency. Here, we broaden the spectrum of suitable reactions to galvanic exchange processes, or an electrochemical replacement of a solid metal layer with dissolved ionic species of a more noble metal. We study the details of motility and the influence of different reaction parameters to conclude that these galvanophoretic processes circumvent several steps that lose efficiency in catalytic micromotors. Furthermore, we investigate the chemical process, the charge, and flow conditions that lead to this highly efficient new type of active motility. Toward a better understanding of the underlying processes, we propose an electrokinetic model that we numerically solve via finite elements.

中文翻译：

---

由电化学交换反应驱动的高效活性胶体

微型电机由多种化学反应推动，其中大多数具有催化性质。然而，有一些基于氧化还原反应的系统显示出明显的效率优势。在这里，我们拓宽了适用于电化学交换过程的反应范围，或者用溶解的更贵金属的离子物质对固体金属层进行电化学置换。我们研究了运动的细节和不同反应参数的影响，得出结论，这些电流电泳过程绕过了几个在催化微电机中失去效率的步骤。此外，我们研究了导致这种高效新型主动运动的化学过程、电荷和流动条件。为了更好地理解底层过程，