Nanofluidic system with electrochemical and flow mixing capabilities for in-liquid electron microscopy studies - Phase I

具有电化学和流动混合功能的纳流体系统，用于液体电子显微镜研究 - 第一阶段

• 批准号: 538556-2019
• 负责人: Sciaini, Germán
• 金额: $ 9.11万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Idea to Innovation
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=693386
• 关键词: Nanofluidic; system; electrochemical; flow; mixing

The study of in-liquid samples with nanometre and potentially down to atomic resolution requires the integration of a very specialized nanofluidic cell system (NFCS) into the electron microscope in order to enable transmission electron microscopy (TEM) and electron diffraction/scattering (TED) measurements. A NFCS is therefore a high-tech device (or TEM accessory) capable of manipulating and delivering tiny amounts of liquid to the electron beam path for observation. The NFCS comprises and a nanofluidic cell (NFC) and a nanofluidic holder (NFCHs), which are mutually sealed to prevent liquid leaks and preserve the vacuum integrity inside the electron microscope column. The designs of NFCSs are conceptually simple; however, achieving true control of the liquid flow, and up to some extend of the thickness of the liquid layer across the viewing windows of the NFC continues to be an unsolved challenge for current NFCS manufacturers. The strongly interacting nature of electrons with matter leads to the necessity of implementing a very short electron beam (often within 100 nm - 1000 nm) with very thin silicon nitride films (10 nm - 100 nm) as windows. Although capillary forces may initially help, the reduced cross-sectional area of the nanochannel creates a large resistance to flow and with that pressure builds up in the inlet. Despite their very high cost, the design of commercial state-of-the-art NFCSs is way too simple to ensure true liquid flow; i.e. the resistance for liquid to flow through the nanochannel is so large that most of the fluid goes around the NFC sandwich while any effort to force the liquid path would lead to window bulging and the deterioration of image quality. UW nanofluidic technology circumvented the aforementioned issues, enabling true control of the liquid flow rate, which in combination with fluid mixing and in situ electrochemistry capabilities will allow for realization of new and exciting in situ TEM experiments. The creation of a start-up in Waterloo region is anticipated (ca. fall 2020).

对纳米级和可能低至原子级分辨率的液体样品的研究需要将非常专业的纳米流体单元系统（NFCS）集成到电子显微镜中，以便实现透射电子显微镜（TEM）和电子衍射/散射（TED）测量。因此，NFCS是一种高科技设备（或TEM配件），能够操纵并将微量液体输送到电子束路径进行观察。NFCS包括纳米流体单元（NFC）和纳米流体保持器（NFCH），它们相互密封以防止液体泄漏并保持电子显微镜柱内的真空完整性。NFCS的设计在概念上是简单的;然而，实现对液体流动的真正控制，以及跨NFC的观察窗的液体层的厚度的某种程度，对于当前的NFCS制造商来说仍然是一个未解决的挑战。电子与物质的强烈相互作用性质导致必须以非常薄的氮化硅膜（10 nm-100 nm）作为窗口来实现非常短的电子束（通常在100 nm-1000 nm内）。尽管毛细力最初可能有所帮助，但纳米通道的横截面积减小会产生较大的流动阻力，并且随着入口中的压力增加。尽管它们的成本非常高，但是商业上最先进的NFCS的设计太简单而不能确保真正的液体流动;即，液体流过纳米通道的阻力太大，以至于大部分流体绕过NFC夹层，而任何迫使液体路径的努力都将导致窗口凸出和图像质量的劣化。UW纳米流体技术规避了上述问题，能够真正控制液体流速，与流体混合和原位电化学能力相结合，将允许实现新的和令人兴奋的原位TEM实验。预计将在滑铁卢地区创建一家初创企业（约100万美元）。2020年秋季）。