Electron Microscopy: Liquid‐Flowing Graphene Chip‐Based High‐Resolution Electron Microscopy (Adv. Mater. 2/2021)

Graphene Electrode for Studying CO2 Electroreduction Nanocatalysts under Realistic Conditions in Microcells

“…Previous studies that used graphene to seal the liquid TEM cells have demonstrated the stability of graphene at a pressure differential of 3–6 bar while remaining well‐adhered at liquid flow rates of up to 120 µL min −1 for three stacked layers and above. [ 14 ]…”

“…Concerning graphene membranes, it has been previously reported that their bulging increases with the increase of hole diameter. [ 14 ] Thus, for the 1–3 µm diameter‐sized holes, we expect the graphene membrane to have little influence on the bulging of the microcell, which will be defined by the properties of the SiN x membrane. However, in the case of secondary electron (SE) detection in SEM, the spatial resolution is primarily dependent on the thickness of the membrane whereas the absolute liquid thickness does not influence the SEM resolution, which becomes limiting in transmission electron studies.…”

“…[ 13 ] Hence, graphene cells of different generations are reported to exhibit less bulging and enable thinner liquid layers, allowing high‐resolution imaging of materials in liquid media. [ 7,14 ] Furthermore, the development of MEMS‐based graphene chips has enabled precise control over the liquid environment and thickness, in contrast to the initial design of graphene cells using a veil‐type configuration where the liquid is trapped into pockets formed via Van der Waals interactions of two graphene sheets. [ 14–16 ] Recently, Tan et al.…”

“…[ 7,14 ] Furthermore, the development of MEMS‐based graphene chips has enabled precise control over the liquid environment and thickness, in contrast to the initial design of graphene cells using a veil‐type configuration where the liquid is trapped into pockets formed via Van der Waals interactions of two graphene sheets. [ 14–16 ] Recently, Tan et al. added graphene as an electrode material, on top of the full SiN x membrane‐based ec‐LPTEM cell and demonstrated its use for Cu electroplating and stripping.…”

Single‐Molecule Graphene Liquid Cell Electron Microscopy for Instability of Intermediate Amyloid Fibrils

“…[15] However, additional membranes on the optical axis reduce the spatial resolution and image contrast. [16,17] To observe biological samples with weak image contrast, additional contrast-enhancing treatments, such as tagging or staining, are required; however, this interferes with realistic molecular processes. [18] Graphene liquid cells (GLCs) utilizing carbon-atom-thick graphene as an electron-transparent membrane provide high image contrast.…”