Development of a sealed liquid sample holder for SEM microscopy

The research presented describes steps in the development of sample holders capable of allowing liquid samples to be imaged in a scanning electron microscope (SEM). While SEM imaging has provided extraordinary insights into the morphology of nanoscale systems, their application to soft-matter or liquid samples has been hindered by the requirement that the sample chamber is operated at low-pressure to enable the electron imaging beam. To this end we have developed a procedure to encapsulate thin liquid layers of the solution of interest behind electron transparent windows made of SiN allowing imaging access while maintaining sample integrity. The assembly procedure of the sample holder uses a layer of deposited polystyrene sphere spacers allowing for an easier control of the imaging volume without the need for complex microfabrication.