Grant: Research Tools and Instruments

Membranes made from two-dimensional materials such as graphene promise orders of magnitude higher performance than conventional membranes. This is made possible by the atomic thinness of the material, allowing it to support sub-nanometer pores capable of filtering molecules by size while imposing minimal hydrodynamic resistance to fluid flow. Realizing these membranes on a useful scale will require a detailed understanding of fluid transport across pores in atomically thin materials. However, there remains very little experimental information about such flows and the few experimental studies that have been published report very interesting transport phenomena that are not well understood. *I request funds to purchase an atomic force microscope (AFM) to perform the first measurements of various types of transport through single sub-nanometer pores in atomically thin membranes. I will conduct the first studies measuring the permeance of imaged pore structures, liquid transport across graphene pores, gas permeance enhancement by surface adsorption and diffusion, and the permeance of pores in two-dimensional materials beyond graphene.*Atomic force microscopy is the only tool proven capable of measuring the minuscule flow rates through these systems. However, the time required to develop techniques to observe these flow rates and to measure samples precludes the use of shared equipment. Furthermore, I am starting a new lab in January 2019 and this equipment will accelerate my research program by allowing me to begin experiments within the first year, while I build up the equipment and capabilities needed to pursue my other research objectives. *This equipment is essential to training students to conduct research in experimental sub-nanometer scale fluid mechanics, which will position them to make significant contributions to the interesting but relatively unexplored field of nanofluidics. It will give them an uncommon skillset with which to launch independent research careers and metrology expertise valued in the semiconductor and materials industries.*The research enabled by this equipment will allow us to resolve unanswered questions in transport across sub-nanometer pores in two-dimensional materials and discover yet unknown fluid flow phenomena as the atomic details of boundaries become important. It will advance our understanding of mass transport at the smallest length scale and support research to develop membranes with orders of magnitude higher permeance for applications in clean water and energy.*