自发微图案化柔性磁电子薄膜的制备及其磁电特性研究

With the advent of wearable electronic devices, flexible magnetoelectric thin film sees wide application in electronic skins and other flexible electronics. Micro- or nano-patterned structures play an important role in modifying the magnetism, electron transportation, strain behavior, and frequency selection of the flexible magnetoelectric thin films. However, the high cost of conventional lithography technologies and the poor mechanical and thermal stabilities of flexible substrates seriously hinder the large-area fabrication of the periodic patterned flexible magnetoelectric thin films. Fortunately, the good stretchability of the flexible substrate enables the microstructural control of the top layer by strain engineering. Accordingly, this project attempts to develop a novel patterning method called strain-induced self-organized micro-patterning, which is applicable to the large-area fabrication of flexible thin films. The basic principle is that a strained superelastic substrate covered with a stiff top layer can generate periodic wrinkle-like micropatterns on its surface when the strain is released. The shape, wavelength and amplitude of the micropattern can be modulated by strain, cover layer element and thickness. Beside the micropatterned magnetic thin films, periodic striped spin valves will be fabricated by oblique sputtering on the wrinkled substrate, maybe with the help of a mask during sputtering. The effects of micropatterns and strain on the magnetism and electron transportation of the patterned magnetic thin films and periodic spin valves will be investigated. It is expected that this research could provide scientific guidance for the design of novel wearable magnetoelectronic devices, especially flexible magnetic/strain sensors and microwave absorber.

随着可穿戴设备的兴起，柔性磁电子薄膜在电子皮肤等领域获得了广泛应用。在柔性磁电薄膜器件中，人工的微纳图案结构对其磁性、电子输运、应力特性和频率响应等的调控起着重要作用。但是，传统的光刻、纳米压印等微加工技术昂贵的成本以及柔性衬底的力学、热学不稳定性都不利于柔性磁电薄膜微图案结构的大面积制备。然而，柔性衬底良好的弹性却为应力调控薄膜微结构提供了便利。本项目拟研发一种可用于大面积制备的柔性磁电薄膜的自发微图案化方法，即通过超弹性有机衬底上的应力工程实现对柔性磁电薄膜微结构的调控，获得形状和周期可控的自发微图案结构；在此基础上利用倾斜溅射获得对应力和磁场敏感的条带状周期性自旋阀；研究微图案化柔性磁电薄膜中应力-微结构-磁电性能之间的相互关联，分别获得应力对微结构、应力对磁电性能、微结构对磁电性能的调控机制。本研究将为微图案化柔性磁电薄膜在柔性应力/磁场传感器和高频等领域的应用提供参考。

随着可穿戴设备的兴起，柔性磁电子薄膜在电子皮肤等领域获得了广泛应用。在柔性磁电薄膜器件中，人工的微纳图案结构对其磁性、电子输运、应力特性和频率响应等的调控起着重要作用。但是，传统的光刻、纳米压印等微加工技术昂贵的成本以及柔性衬底的力学、热学不稳定性都不利于柔性磁电薄膜微图案结构的大面积制备。然而，柔性衬底良好的弹性却为应力调控薄膜微结构提供了便利。本项目拟研发一种可用于大面积制备的柔性磁电薄膜的自发微图案化方法，即通过超弹性有机衬底上的应力工程实现对柔性磁电薄膜微结构的调控，获得形状和周期可控的自发微图案结构；在此基础上利用倾斜溅射获得对应力和磁场敏感的条带状周期性自旋阀；研究微图案化柔性磁电薄膜中应力-微结构-磁电性能之间的相互关联，分别获得应力对微结构、应力对磁电性能、微结构对磁电性能的调控机制。本研究将为微图案化柔性磁电薄膜在柔性应力/磁场传感器和高频等领域的应用提供参考。