Nanofluidic Cells with Controlled Path Length and Liquid Flow for Rapid, High-Resolution In Situ Electron Microscopy

Abstract

ABSTRACTIn situ imaging using (scanning) transmission electron microscopy has proven to be an extremely important and powerful cross-disciplinary scientific technique. In particular nanotechnology and materials sciences have special interest in assembly and disintegration processes, in growth and shape-tuning of (nano)-particles, and, furthermore in mechanistic studies of chemical reactions underlying these processes. However, limitations for in liquid and in situ imaging using electron microscopy arise from the stringent experimental conditions required with respect to electron scattering.Here, we present a nanofluidic sample cell allowing for controlled fluidic conditions which preserve the highest possible spatial resolution for in-liquid electron microscopy. The nanocell allows for liquid flow with a flow control mechanism operated external to the microscope column enabling on-the-fly sample exchange within the imaging area. A well-defined flow path allows us to direct the motion of gold nanorods through fluid flow. Further a particle’s Brownian motion becomes evident once the external flow is terminated. In addition to quantitatively showing the resolution capabilities of our nanofluidic design, we show preliminary results of in situ imaging of gold nanorods and unstained amyloid fibrils to emphasize the significance of this imaging modality for both material sciences and biology.