Revealing Dynamic Processes of Materials in Liquids Using Liquid Cell Transmission Electron Microscopy
Revealing Dynamic Processes of Materials in Liquids Using Liquid Cell Transmission Electron Microscopy
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DOI：
10.3791/50122
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发表时间：
2012-12-01
影响因子：
1.2
通讯作者：
Zheng, Haimei
中科院分区：
文献类型：
--
作者：
Niu, Kai-Yang;Liao, Hong-Gang;Zheng, Haimei
原位透射电子显微镜的最新发展使其能够通过液体进行高空间分辨率的成像，引起了材料科学、物理、化学和生物等领域的极大兴趣。关键的使能技术是液体电池。我们通过一系列微加工工艺，包括氮化硅薄膜沉积、光刻图形、晶片刻蚀、单元键合等，制造出具有薄观察窗口的液晶盒。大约100纳升的反应溶液被装载到储液器中，并且大约30皮升的液体被毛细管力吸引到观察窗中。随后，将细胞密封并装载到显微镜中进行原位成像。在电子显微镜内部，电子束穿过夹在两层氮化硅薄膜之间的薄液层。纳米粒子在液体中的动态过程，如纳米粒子的成核和生长、纳米粒子的扩散和组装等，都可以在亚纳米分辨率下实时成像。我们还将这种方法应用于其他研究领域，例如对水中的蛋白质进行成像。液胞透射电子显微镜有望在揭示材料在其工作环境中的动态过程方面发挥重要作用。它还可能对研究其自然环境中的生物过程产生很大影响。
The recent development for in situ transmission electron microscopy, which allows imaging through liquids with high spatial resolution, has attracted significant interests across the research fields of materials science, physics, chemistry and biology. The key enabling technology is a liquid cell. We fabricate liquid cells with thin viewing windows through a sequential microfabrication process, including silicon nitride membrane deposition, photolithographic patterning, wafer etching, cell bonding, etc. A liquid cell with the dimensions of a regular TEM grid can fit in any standard TEM sample holder. About 100 nanoliters reaction solution is loaded into the reservoirs and about 30 picoliters liquid is drawn into the viewing windows by capillary force. Subsequently, the cell is sealed and loaded into a microscope for in situ imaging. Inside the TEM, the electron beam goes through the thin liquid layer sandwiched between two silicon nitride membranes. Dynamic processes of nanoparticles in liquids, such as nucleation and growth of nanocrystals, diffusion and assembly of nanoparticles, etc., have been imaged in real time with subnanometer resolution. We have also applied this method to other research areas, e.g., imaging proteins in water. Liquid cell TEM is poised to play a major role in revealing dynamic processes of materials in their working environments. It may also bring high impact in the study of biological processes in their native environment.