MRI: Acquisition of a Field Emission Cryo-Scanning Electron Microscope for Nanocharacterization and Patterning of Soft Materials

MRI：获取场发射冷冻扫描电子显微镜，用于软材料的纳米表征和图案化

• 批准号: 0922522
• 负责人: Matthew Libera
• 金额: $ 69.98万
• 依托单位: Stevens Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-10-01 至 2012-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0922522&HistoricalAwards=false
• 关键词: MRI; Acquisition; Field; Emission; Cryo

0922522LiberaStevens Institute of TechnologyTechnical Summary: This project applies a new, state-of-the-art, cryo-scanning electron microscope (SEM) to measure soft-materials morphology at high spatial resolution. This new microscope will advance over ten research projects at Stevens Institute of Technology and enable them to follow important directions that amplify their ongoing and anticipated aims. All involve soft materials ? either synthetic polymers, biological structures, or combinations of the two. Among the materials being studied are: self-assembled, weak-polyelectrolyte, responsive micelles; nanoparticle composites; degradable scaffolds that mimic natural bone; infection-resistant orthopedic implants; natural extracellular matrix; and synthetic nanofiber extracellular matrices. Synthetic and natural polymers are challenging materials to study by electron microscopy because of their radiation sensitivity, weak intrinsic contrast, and susceptibility to electrical charging. This new microscope provides controllable electron accelerating voltages enabled at low voltages by a field-emission (FEG) electron source; gas compensation to mitigate specimen charging; high-efficiency electron detectors that minimize the required incident dose; robust methods for digital image acquisition/processing; cryo-imaging capabilities for studying frozen-hydrated materials; and hardware/software for robust electron-beam lithography. All of these features are either inadequate or unavailable on the SEM the new microscope replaces. Importantly, the new SEM is housed in a central user facility with a history of successful multidisciplinary training that spans high school through post-graduate school. Users receive substantial training both by concentrated hands-on self-user practice and by graduate lecture/lab course work. In addition to serving the immediate Stevens research community, the instrument plays an important role in community outreach and education by way of collaborative activities with the Stevens Center for Innovative Engineering and Science Education, an established K-16 outreach organization, and the Project SEED program of the American Chemical Society.Layman Summary: Scanning electron microscopes (SEMs) are used to study the surfaces of materials at magnifications between about 20 and 500,000 times. They can provide important information about the structure and composition of materials. So-called soft materials, such as plastics and biological tissue, are typically more challenging to study by electron microscopy than metals or semiconductors, because soft materials can become both electrically charged and chemically changed by the electrons used in the microscope. At Stevens Institute of Technology there are more than ten research projects, all of which involve soft materials, whose progress is limited by the need to do more and better SEM imaging and analysis. The newest scanning electron microscopes incorporate innovative features that can help Stevens researchers overcome the problems of specimen charging and chemical damage. To take advantage of these, this project is using a new, state-of-the-art, SEM to measure soft-materials morphology and help Stevens researchers make new discoveries. These scientists are, for example, using the microscope to develop new ways to delivery drugs, to make hip and knee implants more infection resistant, and to help heal major bone fractures. Because this new microscope is a complex instrument, it is housed in a laboratory with a dedicated staff and facilities to both maintain the microscope and provide the advanced training needed for university students to make the best use of this new tool. Importantly, however, many aspects of the microscope are relatively easy to use and understand, so this microscope is also helping Stevens develop connections to the surrounding community through a variety of high-school outreach programs designed to get more young people aware of and interested in science and engineering.

0922522Liberastevens技术技术摘要：该项目应用了一个新的，最先进的，冷冻扫描的电子显微镜（SEM），以高空间分辨率测量软性形态。 这个新的显微镜将推进史蒂文斯技术学院的十项研究项目，并使他们能够遵循重要的方向来扩大其持续和预期的目标。 所有都涉及软材料吗？合成聚合物，生物结构或两者的组合。 所研究的材料包括：自组装，弱聚电解质，反应胶束；纳米颗粒复合材料；模仿天然骨的可降解脚手架；抗感染的骨科植入物；天然细胞外基质；和合成纳米纤维外矩阵。 合成和天然聚合物由于其辐射敏感性，固有的对比度弱以及对电荷的易感性而具有挑战性通过电子显微镜研究的材料。该新的显微镜提供可控的电子加速电压，该电压在低电压下通过电场发射（FEG）电子源启用；气体补偿以减轻样品充电；最小化所需的入射剂量的高效率电子检测器；数字图像采集/处理的强大方法；用于研究冷冻水合材料的冷冻成像功能；以及用于强大电子梁光刻的硬件/软件。 所有这些功能在SEM上都是不足或不可用的新显微镜替代。 重要的是，新的SEM设在中央用户设施中，并拥有成功的多学科培训的历史，该培训跨越了高中。 用户通过集中的动手练习和研究生讲座/实验室课程工作，都可以接受大量的培训。 除了为史蒂文斯研究社区服务外，该乐器还通过与史蒂文斯创新工程和科学教育中心的合作活动，一个既定的K-16外展组织以及美国化学学会的项目种子计划，在社区宣传和教育中发挥着重要作用，美国化学学会的项目种子计划。莱曼化学摘要：扫描电子微观（SEMS）（SEMS）的范围20的材料范围为20个材料。 他们可以提供有关材料结构和组成的重要信息。 与金属或半导体相比，通过电子显微镜研究的所谓软材料（例如塑料和生物组织）通常更具挑战性，因为软材料可以通过显微镜中使用的电子进行电动和化学变化。 在史蒂文斯技术学院，有十个以上的研究项目，所有这些项目都涉及软材料，这些项目的进步受到需要进行更多更好的SEM成像和分析的限制。 最新的扫描电子显微镜结合了创新功能，可以帮助史蒂文斯研究人员克服标本充电和化学损伤的问题。 为了利用这些优势，该项目正在使用一个新的，最先进的SEM来衡量软体材料的形态，并帮助史蒂文斯的研究人员做出新的发现。 例如，这些科学家使用显微镜开发新的递送药物，使髋关节和膝盖植入物更具感染性感染，并帮助治愈主要的骨折。 由于这种新的显微镜是一种复杂的工具，因此它位于实验室中，该实验室拥有专门的员工和设施，以维护显微镜，并为大学生提供最佳利用该新工具所需的高级培训。 然而，重要的是，显微镜的许多方面相对易于使用和理解，因此该显微镜还通过各种旨在使更多年轻人了解和对科学和工程感兴趣的年轻人来帮助史蒂文斯建立与周围社区的联系。