By using graphene membranes as viewing 'windows', researchers have filmed nanocrystals growing in liquids at atomic resolution.

Studying structures in liquids at the atomic level is challenging because the imaging technique of choice, transmission electron microscopy, requires that samples be in a vacuum to maximize their interactions with the electron beam. Air-tight capsules can be used to enclose liquids, but are thick and made of materials that interfere with passing electrons, resulting in a blurred picture. Membranes made of graphene — atomically thin sheets of carbon atoms — are both impermeable to liquids and much more transparent to electrons.

Paul Alivisatos at the Lawrence Berkeley National Laboratory in Berkeley, California, and his colleagues used these graphene windows to create atomic-resolution movies of platinum nanocrystals clumping together in a liquid.

Science 336, 61–64 (2012)