Oscillation plays a vital role in the survival of living organisms in changing environments, and its relevant research has inspired many biomimetic approaches to soft autonomous robotics. However, it remains challenging to create mechanical oscillation that can work under constant energy input and actively adjust the oscillation mode. Here, a steam-driven photothermal oscillator operating under constant light irradiation has been developed to perform continuous or pulsed, damped harmonic mechanical oscillations. The key component of the oscillator comprises a hydrogel containing Fe₃O₄/Cu hybrid nanorods, which can convert light into heat and generate steam bubbles. Controllable perturbation to the thermomechanical equilibrium of the oscillator can thus be achieved, leading to either continuous or pulsed oscillation depending on the light intensity. Resembling the conventional heat steam engine, this environment-dictated multimodal oscillator uses steam as the working fluid, enabling the design of self-adaptive soft robots that can actively adjust their body functions and working modes in response to environmental changes. An untethered biomimetic neuston-like robot is further developed based on this soft steam engine, which can adapt its locomotion mechanics between uniform and recurrent swimming to light intensity changes and perform on-demand turning under continuous light irradiation. Fueled by water and remotely powered by light, this unique hydrogel oscillator enables easy control over the oscillation dynamics and modes, offering an effective approach to self-adaptive soft robots and solar steam engines.

中文翻译：

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用于自适应振荡和仿生游泳的光动力软蒸汽机

振荡对于生物体在不断变化的环境中的生存起着至关重要的作用，其相关研究激发了许多软自主机器人的仿生方法。然而，创造可以在恒定能量输入下工作并主动调整振荡模式的机械振荡仍然具有挑战性。在这里，已经开发了一种在恒定光照射下运行的蒸汽驱动光热振荡器，以执行连续或脉冲的阻尼谐波机械振荡。振荡器的关键部件包括含有 Fe ₃ O _{4的水凝胶}/Cu杂化纳米棒，可以将光转化为热并产生蒸汽泡。因此可以实现对振荡器的热机械平衡的可控扰动，根据光强度导致连续或脉冲振荡。类似于传统的热蒸汽机，这种环境主导的多模态振荡器以蒸汽为工作流体，可以设计出自适应软机器人，可以根据环境变化主动调整身体功能和工作模式。在这种软蒸汽机的基础上，进一步开发了一种无束缚仿生类neuston机器人，该机器人可以使其在匀速游泳和循环游泳之间的运动力学适应光照强度的变化，并在连续光照下进行按需转向。