Hummingbird Scientific’s SEM gas system encloses the sample within a microfabricated gas cell in the holder tip, which is sealed from the microscope chamber environment by a patented sealing mechanism. The gas delivery system and heating controller or electrical biasing electronics are located outside of the chamber. Using Hummingbird’s two-chip gas cell, users can prepare their sample of choice using the same methods they would for any other electron transparent membrane substrate.