Fig. 3: Structural reconstructions and polymer entanglements of photoresist within liquid films.

a 3D tomogram reconstruction of photoresist polymers in the vitrified liquid film. b Spatial locations of photoresist densities in (a). The blue spots represent the photoresist densities. c Size distributions of photoresist polymers at the gas-liquid interface (blue) and in the ice layer (red). d Schematic of two types of polymer entanglements: localized parallel segments in cohesional entanglement (top) versus physically interlocked loops in topological entanglement (bottom). e 3D reconstructions of parallel chain segments indicating the cohesional entanglement between photoresist molecules. f Representative 3D reconstructions of entangled polymers from gas-liquid interface. The sub-5 nm spacings between polymer chains can be resolved. g A comparative radar plot benchmarking cryo-ET against conventional imaging methods^12,13,14,15 across five metrics: resolution, native-state preservation, 3D structural reconstruction, interface distribution analysis, and polymer entanglement characterization.