Advancing Research on Biomaterials and Biological Materials with Scanning Electron Microscopy under Environmental and Low Vacuum Conditions

In this article, a general introduction to the fundamental principles of environmental scanning electron microscopy (ESEM) is given and its advantages in comparison to conventional SEM is illustrated through selected application examples from life sciences, focusing on biomaterial research and biology. Conventional SEM is a well-established and widely used technique to characterize material properties and surface structures in a variety of research fields. However, due to the high vacuum conditions used in conventional SEM, imaging delicate, nonconductive, and/or wet samples—which are particularly prevalent in life sciences—normally requires extensive sample preparation, such as critical point drying and sputter-coating, which can alter the sample properties. Here, ESEM offers a convenient solution, where nonconductive and wet biological samples can be imaged in their near-native state almost without sample preparation. The advantages of ESEM compared to conventional SEM for life sciences based on examples from literature and new application examples from biomaterials science and zoology are illustrated. Finally, recent advances in automated imaging and AI-based image processing are beginning to extend the current limits of resolution and sample stability in ESEM, potentially enabling more precise, real-time, and less damaging imaging of hydrated and beam-sensitive materials in future studies.