Tabletop Scanning Electron Microscope (HITACHI TM4000Plus II)
The Hitachi TM4000Plus II is a benchtop scanning electron microscope (SEM) that allows for the observation of hydrated samples without the need for prior metallization. This technique brings the advantage to work with non-conductive samples in low vacuum conditions. Environmental scanning microscopy is based on the emission of a thermionic electron beam from the tungsten filament, where secondary electrons and backscattered electrons give information about the topography and composition of the sample, respectively.
This environmental SEM is particularly adapted to the observation of biofilms, as portrayed in the figure below of a microplastic recovered from the Mediterranean Sea after 3 weeks of immersion, where we can observe bacteria and diatoms embedded in a polymeric matrix colonizing the surface.