Environmental scanning electron microscope (ESEM)
Environmental SEM is a scanning electron microscope that enables observation of non-conductive, wet, outgassing or dynamic samples without coating. The ESEM uses a variety of environments inside the chamber manipulating pressure, humidity, temperature, or even the composition of ambient gas or liquid. The ESEM is equipped by an environmental secondary electron detector which uses the gas in the environment to amplify the secondary electron signal.
In CIME, we do not have an ESEM, but the Zeiss GeminiSEM 300 allows besides HV (high vacuum) mode also variable pressure (VP) mode and Nano VP mode to observe non-conductive samples without any need for special specimen preparation. (Since it is not an ESEM, we cannot observe wet or outgassing samples.)