Liquid cell transmission electron microscopy and its applications

Abstract

Transmission electron microscopy (TEM) has long been an essential tool for understanding the structure of materials. Over the past couple of decades, this venerable technique has undergone a number of revolutions, such as the development of aberration correction for atomic level imaging, the realization of cryogenic TEM for imaging biological specimens, and new instrumentation permitting the observation of dynamic systems in situ . Research in the latter has rapidly accelerated in recent years, based on a silicon-chip architecture that permits a versatile array of experiments to be performed under the high vacuum of the TEM. Of particular interest is using these silicon chips to enclose fluids safely inside the TEM, allowing us to observe liquid dynamics at the nanoscale. In situ imaging of liquid phase reactions under TEM can greatly enhance our understanding of fundamental processes in fields from electrochemistry to cell biology. Here, we review how in situ TEM experiments of liquids can be performed, with a particular focus on microchip-encapsulated liquid cell TEM. We will cover the basics of the technique, and its strengths and weaknesses with respect to related in situ TEM methods for characterizing liquid systems. We will show how this technique has provided unique insights into nanomaterial synthesis and manipulation, battery science and biological cells. A discussion on the main challenges of the technique, and potential means to mitigate and overcome them, will also be presented.

Current-Density-Dependent Electroplating in Ca Electrolytes: From Globules to Dendrites

“…This is most likely because the diffusion of the Ca ions is limited within the confined submicron space between the encapsulating cell membranes, a phenomenon that has been previous reported in liquid-cell TEM set-ups. [32][33][34][35] Our presented in-situ TEM studies are consistent with the expected model for the current density dependence of electroplating morphology, however deviations from it were observed. Figure 4a i shows the morphology of a further Ca deposit plated under the same conditions as the 10 mA cm -2 deposition in Figure 3a.…”

Detection of Oxidative Stress Induced by Nanomaterials in Cells—The Roles of Reactive Oxygen Species and Glutathione

“…In addition to the most frequently used methods, other approaches have been used to characterize the cellular nanotoxicity recently. These methods include scanning electron microscopy [ 185 ], liquid cell transmission electron microscopy [ 186 ], atomic force microscopy [ 187 ], and hyperspectral and laser confocal microscopy applied to cell-nanoparticles interactions [ 185 ]. All these microscopic methods are very sensitive and specific, which allows for a very detailed description of the function state of the cells after nanomaterials treatment.…”

Recent Progress in Using Graphene as an Ultrathin Transparent Support for Transmission Electron Microscopy

“…Different architectures have been used till date to fabricate liquid cells for microscopy purposes. [ 177 ] Among all the approaches, the use of graphene as a window material for the fabrication of liquid cells, also known as graphene liquid cells (GLCs), has been used extensively and has consistently been proved to be a better candidate than conventional windows for high‐resolution imaging of beam‐sensitive specimens. [ 102 ] The architecture of such cells comprises only layers of graphene to encapsulate liquid specimens.…”