MRI: Acquisition of a Scanning Electron Microscope with In Situ Capabilities

非技术摘要摄影记录了时间上的瞬间，但电影捕捉到了从一个时刻到下一个时刻发生的变化。想想一只从鸡蛋孵化出来的小鸡，与一张鸡蛋的照片和另一张小鸡的照片相比，一部电影提供的信息要多得多。在材料的研究中，我们感兴趣的是固体对各种环境和刺激的反应。在过去，我们通过制作许多重复的样本并在几个时间点停止转换来拍摄基本上是静止的照片，然后尝试连接这些时间点之间的点，来研究材料中的过渡。这种方法既繁琐又缓慢，更不用说充满了遗漏信息的不确定性。这种新仪器使研究人员能够在刺激材料的同时记录它们的反应。我们的成像方法检测到的化学和拓扑特征比人类头发的厚度小500倍，还允许在这个长度尺度上进行样本操作。对于设计一种新材料的非凡性能来说，重要的刺激因素包括接触液体和气体、温度控制、电场和机械变形。将被研究的材料具有广泛的应用，包括用于燃料电池的膜、高灵敏度的化学传感器、柔性电子、工程涂层、用于组织工程的结构化表面和高效太阳能电池。该仪器将被整合到我们高度成功、配备专业人员的地区设施中，该设施向所有学术、工业和政府科学家和工程师开放。技术摘要新型扫描电子显微镜配备了一系列独特的附件，使高分辨率成像和纳米级操作相结合，实现了涉及受控刺激和相关响应的强大的原位实验。原位能力包括纳米尺度的样品操纵，以及暴露在流体、气体、电场、光、机械变形和温度中。该仪器实现的原位方法不仅比涉及多个仪器和暴露在空气中的“进出”程序更清洁和更有效，而且还使理解纳米级基本过程的全新举措成为可能，尽管风险很高。将要进行的实验远远超出了结构成像的范畴，同时将这一基本特征作为一项基本要素纳入其中。我们还将获得一台具有数字成像/记录功能的光学显微镜；这将作为样本筛选和初步测量的“前端”，以告知和确保扫描电子显微镜的最佳使用。来自7个系、代表各个级别的17名教职员工设想并计划在纳米科学的四个专题领域内为这台新仪器进行非凡的实验：电响应材料(包括燃料电池膜、柔性电子学和纳米电路)、相变(包括超晶格、相分离和图案化)、表面现象(包括润湿、细胞响应、气体吸附和自组装)和机械响应材料(包括硬材料、蛋白质和流体)。用户基础将为启动新的协作、互动和培训/教育举措提供一个协调中心。该仪器将被纳入我们高度成功、配备专业人员的地区设施中，该设施向学术界、工业界和政府的科学家和工程师开放。为鼓励本地文理学院全面参与，特别是高度挑剔的女子学院布林莫尔学院，我们会为这些院校的研究人员提供技术援助和机器使用。

Non-Technical AbstractPhotography records a moment in time, but movies capture the transformations that occur from one moment to the next. Consider a chick hatching from an egg and how much more informative a movie is as compared to one photograph of the egg and another of the chick. In the study of materials, we are interested in how solids respond to various environments and stimuli. In the past we have studied transitions in materials by making many duplicate samples and stopping the transformation at a few time points to take essentially still photographs and then attempting to connect the dots between these time points. This approach is tedious and slow, not to mention riddled with uncertainties about missed information. The new instrument enables researchers to stimulate materials and record their response at the same time. Our imaging method detects chemical and topological features 500 times smaller than the thickness of a human hair, and also allows for sample manipulation on this length scale. Stimuli that are important for designing extraordinary properties into a new material include exposure to liquids and gases, temperature control, electric fields, and mechanical deformation. The materials to be studied have a wide variety of applications including membranes for fuel cells, highly sensitive chemical sensors, flexible electronics, engineered coatings, structured surfaces for tissue engineering, and high-efficiency solar cells. The instrument will be incorporated into our highly successful, professionally staffed regional facility that is open to all academic, industrial, and governmental scientists and engineers. Technical AbstractThe new scanning electron microscope is equipped with a uniquely broad array of accessories to enable the combination of high-resolution imaging and nanoscale manipulation for powerful in situ experiments involving controlled stimuli and correlated response. In situ capabilities include nanoscale manipulation of specimens and exposure to fluids, gases, electrical fields, light, mechanical deformation, and temperature. The in situ approach enabled by this instrument is not only cleaner and more efficient than "in-and-out" procedures involving multiple instruments and exposure to air, it also makes possible entirely new, albeit high risk, initiatives to understand fundamental processes at the nanoscale. The experiments to be conducted go far beyond structural imaging, while incorporating this basic feature as an essential ingredient. We will also acquire an optical microscope with digital imaging/recording; this will serve as a "front end" for sample screening and preliminary measurements to inform and ensure the optimum use of the SEM. Seventeen faculty members associated with seven departments and representing all ranks have envisioned and planned remarkable experiments for this new instrument within four topical areas of nanoscale science: electrically responsive materials (including fuel cell membranes, flexible electronics, and nano circuitry), phase transitions (including superlattices, phase separation, and patterning), surface phenomena (including wetting, cell response, gas adsorption, and self-assembly), and mechanically responsive materials (including hard materials, proteins, and fluids). The user base will provide a focal point for initiating new collaborations, interactions and training/education initiatives. The instrument will be incorporated into our highly successful, professionally staffed regional facility that is open to academic, industrial, and governmental scientists and engineers. To encourage the full participation of local liberal arts colleges, particularly the highly selective women's college Bryn Mawr College, we will provide technical assistance and machine use to researchers from these institutions.