Graphene liquid cells are nano to microscale pockets of water sealed in two layers of graphene. Around the pocket, the two graphene layers stick together due to strong static forces, giving rise to a very stable pocket that is both water and vacuum tight. Graphene liquid cells form an ideal platform to study samples in liquid in transmission electron microscopy, where the ultra-thin graphene function as the most electron transparent window currently available. In graphene liquid cells, samples sustain significantly reduced harm the electron beam irradiation due to graphene’s well-attested protective effects. Furthermore, using Vitrotem patented spacer technology, the thickness of the liquid layer in the liquid cells can straightforwardly be optimized. The optimal liquid cell thickness is found close to the sample dimensions; accommodating the sample without deformation while offer the thinnest possible structure to minimally obstruct the transmission electron beam.

Samples in graphene liquid cells are dissolved and hydrated, retaining in many aspects their native state. With graphene liquid cells, drying, freezing or fixating are no longer required. The room-temperature assembly processes drastically simplify the sample preparation compared to cryo-EM methods. The resulting ultra-thing structures lead to high resolution imaging of biological and organic matter without the need for staining. Application areas include the direct sub-nanometer resolution imaging of proteins, nanomaterials and in particular metallic nanoparticles at atomic resolution.