Graphene-sealed Si/SiN cavities for high-resolution in situ electron microscopy of nano-confined solutions

We demonstrate new liquid cell architectures utilizing graphene-sealed Si or SiN cavities for in situ electron microscopy. While previous graphene liquid cell techniques have shown graphene to be an ideal sealing layer and electron-transparent viewing window, they trap irregular geometries of liquid with unknown sample volumes. Our new technique allows for a leak-proof confinement of liquids of precise volume in the tens of attoliter range while maintaining the benefits of graphene as a viewing window. The utility of this new cell architecture is demonstrated by imaging the dynamics of gold nanoparticles in three dimensions with atomic resolution under a transmission electron microscope.