Mr. Ron Bessler, M.Sc. Candidate
Faculty of Materials Science and Engineering
Technion – Israel Institute of Technology Haifa 3200003, Israel
The discovery of graphene has paved the way to numerous possibilities for new and novel inventions in the scientific community. This is attributed to graphene’s superior physical properties, both mechanical and electrical. The interlayer relative dielectric constant εr, of 2-dimensional (2D) material systems in general and graphitic materials in particular, is one of their most important physical properties, especially for electronic applications. In this seminar, I will present our study on electromechanical actuation of nano-scale graphitic contacts using atomic and lateral force microscopy. We find that beside the adhesive forces there are capacitive forces that scale parabolically with the potential drop across the sheared interface. We use this phenomenon to measure the intrinsic dielectric constant of the bilayer graphene interface i.e. εr = 6 ± 2, which is in perfect agreement with recent theoretical predictions for multi-layer graphene structures. In addition, we investigate how the sliding velocity can affect such interlayer forces. We find that the adhesion increases while friction decreases with the increase of velocity. Using FFT analysis, the hopping distance can be observed, showing an increase in the distance with increase of velocity. Our method can be generally used to extract the dielectric and mechanical properties of 2D materials systems and interfaces and our results pave the way for utilizing graphitic and other 2D materials in electromechanical-based applications.