Multi-layer 2D Nanopores for Blue Energy Harvesting: Design, Nanofabrication and Nanofluidic transport

Two-dimensional (2D) materials have allowed the fabrication of few-atom thick, atomically smooth nanopores and nanochannels. The anomalous transport of ions and molecules within such extreme nanostructures strongly depends on the physical confinement, the geometry of the nanofludic device and the physicochemical properties of the materials used. Understanding the importance of those parameters and controlling them at the atomic scale will enable the design of breakthrough technologies in filtration, biology, nanomedicine and energy harvesting. This work focuses on the design, nanofabrication, and characterization of nanopores based on 2D materials for transducing the electrochemical potential difference between fresh water and seawater into an electrical current. We engineered the shape, geometry and material properties of graphene and boron nitride multi-layer nanopores and studied the influence that each of these parameters have on the energy harvesting efficiency and ionic transport. Our devices have proven to be resilient to environmental conditions, mechanically robust and able to harvest from few kW/m^2 up to a maximum of 1.1 MW/m^2 with high efficiency (up to 38%): 6 orders of magnitude higher than commercially available membranes. Finally, we developed a scalable nanofabrication process to build both highly selective ionic conductors and nanofluidic diodes: two fundamental building blocks of the emerging field of iontronics where ions are used as signal carriers to bridge solid-state electronics with biological system with significant implications for biocompatible logic circuits for sensing, and brain-machine interfacing.