Nanofluidic Cells with Controlled Pathlength and Liquid Flow for Rapid, High-Resolution In Situ Imaging with Electrons

The use of electron probes for in situ imaging of solution phase systems has been a long held objective, largely driven by the prospect of atomic resolution of molecular structural dynamics relevant to chemistry and biology. Here, we present a nanofluidic sample cell with active feedback to maintain stable flow conditions for pathlengths varying from 45 nm to several 100 nm, over a useable viewing area of 50 × 50 μm. Using this concept, we demonstrate nanometer resolution for imaging weakly scattering polymer and highly scattering nanoparticles side by side with a conventional transmission microscope. The ability to flow liquids allows control over sample content and on-the-fly sample exchange, opening up the field of high-throughput electron microscopy. The nanofluidic cell design is distinguished by straightforward, reliable, operation with external liquid specimen control for imaging in (scanning) transmission mode and holds great promise for reciprocal space imaging in femtosecond electron diffraction...