The design of artificial microswimmers is often inspired by the strategies of natural microorganisms. Many of these creatures exploit the fact that elasticity breaks the time-reversal symmetry of motion at low Reynolds numbers, but this principle has been notably absent from model systems of active, self-propelled microswimmers. Here we introduce a class of microswimmers that spontaneously self-assembles and swims without using external forces, driven instead by surface phase transitions induced by temperature variations. The swimmers are made from alkane droplets dispersed in an aqueous surfactant solution, which start to self-propel on cooling, pushed by rapidly growing thin elastic tails. When heated, the same droplets recharge by retracting their tails, swimming for up to tens of minutes in each cycle. Thermal oscillations of approximately 5 °C induce the swimmers to harness heat from the environment and recharge multiple times. We develop a detailed elasto-hydrodynamic model of these processes and highlight the molecular mechanisms involved. The system offers a convenient platform for examining symmetry breaking in the motion of swimmers exploiting flagellar elasticity. The mild conditions and biocompatible media render these microswimmers potential probes for studying biological propulsion and interactions between artificial and biological swimmers.

人工微型游泳者的设计往往受到天然微生物策略的启发。这些生物中的许多都利用了弹性破坏了低雷诺数下运动的时间反演对称性这一事实，但这一原理在主动、自走式微型游泳者的模型系统中明显缺失。在这里，我们介绍了一类微型游泳者，它可以在不使用外力的情况下自发地自组装和游泳，而是由温度变化引起的表面相变驱动。游泳者是由分散在表面活性剂水溶液中的烷烃液滴制成的，这些液滴在冷却时开始自行推进，由快速增长的薄弹性尾巴推动。当加热时，相同的液滴通过缩回尾巴来充电，在每个循环中游泳长达数十分钟。大约 5°C 的热振荡促使游泳者利用环境中的热量并多次充电。我们开发了这些过程的详细弹性流体动力学模型，并强调了所涉及的分子机制。该系统提供了一个方便的平台，用于检查利用鞭毛弹性的游泳者运动中的对称性破坏。温和的条件和生物相容性介质使这些微型游泳者成为研究生物推进以及人工和生物游泳者之间相互作用的潜在探针。该系统提供了一个方便的平台，用于检查利用鞭毛弹性的游泳者运动中的对称性破坏。温和的条件和生物相容性介质使这些微型游泳者成为研究生物推进以及人工和生物游泳者之间相互作用的潜在探针。该系统提供了一个方便的平台，用于检查利用鞭毛弹性的游泳者运动中的对称性破坏。温和的条件和生物相容性介质使这些微型游泳者成为研究生物推进以及人工和生物游泳者之间相互作用的潜在探针。