Superlubric particles for friction and wear reduction

Supervisors: Abhishek Gupta and Peter Schall

Friction between moving parts and the associated wear are responsible for about 25% of the world’s energy consumption. Superlubricity is a new mechanism of ultralow friction between solid surfaces, achieved with 2D materials such as graphene when sliding along incommensurate lattice directions (see image below). In this project, we investigate superlubricity and its ability to be scaled up to obtain friction reduction on relevant length scales. NExt to flat graphene surfaces, we use particles coated with superlubric 2D material, which could be used as lubricant. We measure their resistance to shear (rheology), and image the microscopic contacts and particle flow field using 3D confocal microscopy.  To image the atomistic contacts, we explore the natural fluorescence of the 2D materials, which becomes quenched when 2D material layers are atomically close. These microscopic observations complementing the macroscopic mechanical measurements should give unique insight into the micromechanics of ultralow-friction lubricants.

Two layers of graphene (honeycomb structure) on top of each other in commensurate (left) and incommensurate lattice alignment (right)