MRI: Acquisition of A Variable Pressure Scanning Electron Microscope with Serial Block-Face Imaging for Bio and Soft Materials Research

纳米和微米结构在自然界和合成材料中大量存在，它们的技术作用正在迅速增长。 这些小结构的成像是困难的，因为它们太小了，用眼睛或普通光学显微镜看不到。 电子显微镜用电子代替光成像，可以达到必要的放大倍数。 凭借主要研究仪器计划的这一奖项，马萨诸塞州大学阿默斯特电子显微镜中心正在收购具有三个独特功能的扫描电子显微镜：（i）不需要将标本暴露于高真空，（ii）减轻通常在成像过程中积累的电荷，以及（iii）集成切片机。 在后者上进行放大，集成的切片机允许连续切片的标本作为一种手段，收集一系列的二维图像，可以组合成一个单一的，更丰富的三维图像。 该仪器是一种共享资源，支持整个校园以及附近几所本科院校的研究和教学。 马萨诸塞大学阿默斯特分校与美国公司有50多个充满活力的资助研究合作，其中许多合作正在通过表征凝胶，乳液，复合材料，粘合剂，传感器，生物组织和单个细胞等标本的新能力得到加强。 该中心在培养高技能的显微镜专家方面有着良好的记录，新仪器在创新的本科生和研究生实验室课程中发挥着核心作用，这些课程提供电子显微镜的实践培训，这是美国少数机构提供的专业知识。马萨诸塞州大学阿默斯特电子显微镜中心正在获得配备有冷冻台和模块化切片机的可变压力扫描电子显微镜（VP-SEM），用于连续块面成像。该仪器在减压下工作，并提供用于电荷补偿的气体注入，其功能可促进绝缘和/或溶剂化软材料和生命科学样品的成像。结合先进的重建软件，超薄切片机将提供三维映射。 作为一种带有能量色散X射线光谱仪的场发射SEM，其额外功能是三维元素绘图。 这些功能以前在中心都没有。 这些新功能共同推动了针对不同主题的研究，例如：非挥发性和适度挥发性液体的粒子动力学和结构;溶剂化薄膜，膜和凝胶的形态;以及细胞蛋白定位和神经元映射。这些项目跨越校园内外，用户来自马萨诸塞州阿默斯特大学的20个或更多的部门以及附近的7到10所学院。 与现有的高分辨率场发射扫描电子显微镜和能量过滤场发射透射电子显微镜一起放置，VP-SEM补充了一套强大的电子显微镜功能，促进了许多个人研究项目，同时引发材料和生命科学研究人员之间的思想交叉授粉。 除了通过本科和研究生课程访问之外，VP-SEM还将提供给来自合作美国公司的用户，这些公司的数量超过50家。 与马萨诸塞州阿默斯特大学的其他NSF支持的研究项目一起，有吸引力的图像被提供给使用艺术实验室（VISUAL）的科学风险投资，这是一项推广工作，将这些图像，沿着外行的解释，该奖项反映了NSF的法定使命，并通过使用基金会的智力价值进行评估，更广泛的影响审查标准。

Nano- and micro-structures occur abundantly in both the natural world and in synthetic materials, and their technological role is growing rapidly. The imaging of these small structures is difficult, as they are too small to see with the eye or ordinary optical microscope. Electron microscopes, which employ electrons instead of light for imaging, can achieve the necessary magnifications. With this award from the Major Research Instrumentation program, the University of Massachusetts Amherst Electron Microscopy Center is acquiring a scanning electron microscope with three unique features: (i) no requirement for exposing specimens to high vacuum, (ii) mitigation of the charge usually accumulated during imaging, and (iii) an integrated microtome. Amplifying on the latter, an integrated microtome allows serial sectioning of specimens as a means to gather a sequence of two-dimensional images that can be combined into a single, much more informative three-dimensional image. The instrument is a shared resource supporting research and teaching across campus as well as at several nearby undergraduate colleges. UMass Amherst has more than 50 vibrant funded research collaborations with U.S. companies, and many of these collaborations are being strengthened by the new capabilities to characterize specimens such as gels, emulsions, composites, adhesives, sensors, biological tissues, and individual cells. The Center has a strong track record in producing highly skilled microscopists, and the new instrument plays a central role in innovative undergraduate and graduate laboratory courses that afford hands-on training in electron microscopy, an expertise offered at few institutions in the nation.Technical AbstractWith this award from the Major Research Instrumentation program, the University of Massachusetts Amherst Electron Microscopy Center is acquiring a Variable-Pressure Scanning Electron Microscope (VP-SEM) equipped with both a cryo-stage and a modular microtome for serial block-face imaging. The instrument operates at reduced pressure and provides gas injection for charge compensation, features that advance the imaging of insulating and/or solvated soft materials and life science specimens. In conjunction with advanced reconstruction software, the ultramicrotome will afford mapping in three-dimensions. As a field emission SEM with an energy-dispersive x-ray spectrometer, an added capability is three-dimensional elemental mapping. None of these capabilities was previously available in the Center. Together the new capabilities boost research directed at diverse topics such as: particle dynamics and structuring on non-volatile and modestly volatile liquids; morphologies of solvated films, membranes, and gels; and cell protein localization and neuron mapping. These projects span the campus and beyond, and users come from 20 or more University of Massachusetts Amherst departments as well as from 7 to 10 nearby colleges. Placed alongside an existing High-Resolution Field Emission Scanning Electron Microscope and an Energy-Filtered Field Emission Transmission Electron Microscope, the VP-SEM complements a strong suite of electron microscopy capabilities, furthering numerous individual research projects while sparking cross-pollination of ideas between materials and life science researchers. In addition to access through undergraduate and graduate courses, the VP-SEM will be available to users from collaborating U.S. companies, which number more than 50. In conjunction with other NSF-supported research projects at the University of Massachusetts Amherst, attractive images are being provided to Ventures in Science Using Arts Laboratory (VISUAL), an outreach effort that places these images, along with a laymen's explanation, in high track public venues.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.