Actuator operation in increasingly extreme and remote conditions requires materials that reliably sense and actuate at elevated temperatures, and over a range of gas environments. Design of such materials will rely on high-temperature, high-resolution approaches for characterizing material actuation in situ. Here, we demonstrate a novel type of high-temperature, low-voltage electromechanical oxide actuator based on the model material Pr_xCe_1−xO_2−δ (PCO). Chemical strain and interfacial stress resulted from electrochemically pumping oxygen into or out of PCO films, leading to measurable film volume changes due to chemical expansion. At 650 °C, nanometre-scale displacement and strain of >0.1% were achieved with electrical bias values <0.1 V, low compared to piezoelectrically driven actuators, with strain amplified fivefold by stress-induced structural deflection. This operando measurement of films ‘breathing’ at second-scale temporal resolution also enabled detailed identification of the controlling kinetics of this response, and can be extended to other electrochemomechanically coupled oxide films at extreme temperatures.

中文翻译：

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薄膜非化学计量氧化物在极端温度下的动态化学膨胀

在越来越极端和偏远的条件下执行器的操作需要在高温和各种气体环境下可靠地感应和执行操作的材料。这种材料的设计将依赖于高温，高分辨率的方法来原位表征材料的致动。在这里，我们演示了基于模型材料Pr _x Ce _{1 - x} O2 _-δ（PCO）的新型高温，低压机电氧化物致动器。化学应变和界面应力是由电化学方式将氧气泵入或流出PCO膜而导致的，由于化学膨胀，导致可测量的膜体积变化。650岁时 °C时，电偏置值<0.1  V，实现了纳米级位移和> 0.1％的应变，与压电驱动的致动器相比，该值低，并且应力引起的结构变形将应变放大了五倍。薄膜在第二级时间分辨率下“呼吸”的这种操作测量还能够详细识别这种响应的控制动力学，并且可以扩展到极端温度下的其他电化学耦合的氧化物薄膜。