Resolution and aberration correction in liquid cell transmission electron microscopy

Abstract

Liquid cell electron microscopy possesses a combination of spatial and temporal resolution that provides a unique view of static structures and dynamic processes in liquids. Optimizing the resolution in liquids requires consideration of both the microscope performance and the properties of the sample. In this Review, we survey the competing factors that determine spatial and temporal resolution for transmission electron microscopy and scanning transmission electron microscopy of liquids. We discuss the effects of sample thickness, stability and dose sensitivity on spatial and temporal resolution. We show that for some liquid samples, spatial resolution can be improved by spherical and chromatic aberration correction. However, other benefits offered by aberration correction may be even more useful for liquid samples. We consider the greater image interpretability offered by spherical aberration correction and the improved dose efficiency for thicker samples offered by chromatic aberration correction. Finally, we discuss the importance of detector and sample parameters for higher resolution in future experiments. Liquid cell electron microscopy provides a unique combination of spatial and temporal resolution, which is useful for imaging static and dynamic processes in liquids. In this Review, we discuss the resolution expected when imaging liquid specimens in transmission electron microscopy and scanning transmission electron microscopy and consider the benefits of spherical and chromatic aberration for resolution, image interpretability and dose efficiency.