Application of a nanoelectromechanical mass sensor for the manipulation and characterisation of graphene and graphite flakes

This manuscript describes a novel experimental method, employing in-situ experiments inside a scanning electron microscope for the controlled exfoliation of graphene and graphite flakes, their subsequent weighing and transfer onto a substrate surface. All manipulations with graphene and graphite samples were carried out using a Ge nanowire integrated in a nanomanipulation system. The transfer process was based on adhesion interactions between the surfaces of nanowires, graphite and the substrate. The balancing of adhesion forces between the interacting surfaces was realised through varying contact areas between the interrelating surfaces. As well as a tool for transferring graphene and graphite samples, the Ge nanowires also served as a mass sensor, allowing determination of the mass and number of monolayers in each specimen.