MRI: Acquisition of Cryogenic Capabilities for Microanalysis of Hard-Soft Nanoscale Materials in the Transmission Electron Microscope

MRI：获得在透射电子显微镜中对硬软纳米级材料进行微量分析的低温能力

• 批准号: 0521685
• 负责人: Valerie Leppert
• 金额: $ 24.65万
• 依托单位: University of California - Merced
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2008-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0521685&HistoricalAwards=false
• 关键词: MRI; Acquisition; Cryogenic; Capabilities; Microanalysis

Acquisition of cryogenic capabilities for UC Merced's core electron microscopy facility will provide new research opportunities for nanoscale soft-hard materials and for all researchers in the physical and biological sciences, and engineering, at our fledgling campus. In addition, our partner campuses in the NSF Nanoscale Science and Engineering Center: Center Of Integrated Nanomechanical Systems will have access to this unique resource. It offers a combination of advanced microscopy techniques employed for hard materials, such as high-resolution transmission electron microscopy, electron energy-loss spectroscopy (EELS), and X-ray energy dispersive spectroscopy (XEDS), with the cryogenic specimen preparation and handling capabilities necessary for working with soft materials. It will also expand the scope of existing nanotechnology collaborative projects with industrial partners such as Hewlett-Packard. Specifically, the requested cryoultramicrotome will permit rapid freezing and sectioning of hard-soft specimens for TEM and SEM analysis without disruption of internal structures and interfaces that occur with common specimen preparation methods involving dehydration. The cryotransfer stage requested will allow transfer of these specimens into the TEM without warming and, in addition, allow them to be held at liquid nitrogen temperatures during analysis. This capability is critical for soft materials since it decreases specimen damage rates by a factor of 4-10X and prevents carbon migration to the electron beam position that makes microanalysis by thickness-sensitive techniques, such as EELS, otherwise nearly impossible. The combination of EELS, which is highly sensitive to light elements and does not require soft materials to be preferentially stained by heavy elements that introduce artifacts, with cryomicroscopy will enable nanoscale analysis of hard-soft materials in their native state. An XEDS detector has also been requested to complement our existing EELS capabilities. The requested instrumentation will enhance undergraduate teaching and research, in addition to outreach efforts. It will also assist in recruiting highly qualified faculty for our new undergraduate majors in bioengineering (introduced in 2005) and chemistry, materials chemistry, materials science and engineering, and physics (to be introduced in 2006). FTEs for these faculty hires have specifically been allocated in a manner to encourage interdisciplinary collaboration, with soft or soft-hard materials identified as a research focus for all but one of these majors. Combining very small-scale soft materials (polymers and biological materials) and hard materials (semiconductors, ceramics, and metals) leads to development of new technology for applications in human health, the environment; new energy; electronics; and aeronautics requires devices that. In order to understand how these devices work and to enable their development, an electron microscope and specimen preparation equipment are required that can study both the hard and soft components. We propose to combine very cold specimen preparation and holding techniques used for soft specimens with analysis techniques used for hard materials in order to achieve this. Our microscopy facility serves all researchers at our university in the physical sciences, engineering, and biology, and includes undergraduate research and teaching. For example, undergraduate students from our first freshman engineering class (entering in 2005) are already engaged in a microscopy research project that will require them to use these tools. Our students will incorporate their results into an exhibit that they are building for a local science museum serving area middle school students. The results will also be used for a technology education website that the students are developing. This website will in turn be used for interactive technology demonstrations by faculty visiting area middle and high schools.

收购加州大学默塞德分校核心电子显微镜设施的低温能力将为我们羽翼未丰的园区内的所有物理、生物科学和工程研究人员提供纳米级软-硬材料的新研究机会。此外，我们在NSF纳米科学与工程中心：集成纳米机械系统中心的合作伙伴将可以访问这一独特的资源。它结合了用于硬材料的先进显微技术，如高分辨率透射电子显微镜、电子能量损失谱(EELS)和X射线能量色散谱(XEDS)，以及处理软材料所需的低温样品制备和处理能力。它还将扩大与惠普等工业合作伙伴现有纳米技术合作项目的范围。具体地说，所要求的冷冻显微切割机将允许快速冷冻和切片硬-软样品，以进行透射电子显微镜和扫描电子显微镜分析，而不会像常见的脱水样品制备方法那样破坏内部结构和界面。所要求的冷冻转移阶段将允许在不加热的情况下将这些样品转移到透射电子显微镜中，此外，还允许在分析过程中将它们保持在液氮温度下。这种能力对软材料至关重要，因为它将样品损伤率降低了4-10倍，并防止碳迁移到电子束位置，使厚度敏感技术(如EELS)进行微量分析，否则几乎不可能进行分析。鳗鱼对轻元素高度敏感，不需要软材料优先被引入人工制品的重元素染色，与冷冻显微镜相结合，将能够对处于天然状态的硬-软材料进行纳米级分析。XEDS探测器也被要求补充我们现有的EELS能力。除外展工作外，所需仪器还将加强本科生教学和研究。它还将帮助我们为生物工程(2005年引入)和化学、材料化学、材料科学和工程以及物理(2006年引入)的新本科专业招聘高素质的教师。这些教师招聘的FTE是以鼓励跨学科合作的方式专门分配的，软或软硬材料被确定为这些专业中除一个专业外的所有专业的研究重点。将非常小规模的软材料(聚合物和生物材料)和硬材料(半导体、陶瓷和金属)相结合，导致了在人类健康、环境、新能源、电子和航空等领域应用的新技术的发展。为了了解这些设备是如何工作的，并使它们能够发展，需要一台电子显微镜和样品制备设备，可以研究硬部件和软部件。我们建议将用于软样品的非常冷的样品制备和保持技术与用于硬材料的分析技术相结合，以实现这一点。我们的显微镜设备为我们大学的所有物理科学、工程学和生物学的研究人员服务，包括本科生的研究和教学。例如，我们第一个工程类新生(2005年入学)的本科生已经在从事一个显微镜研究项目，这将需要他们使用这些工具。我们的学生将把他们的成果纳入他们正在为当地一家科学博物馆建造的展览中，该博物馆服务于当地的中学生。这一结果还将用于学生正在开发的一个技术教育网站。该网站将用于教师访问该地区的初中和高中的互动技术演示。