Nanofluidic diodes: from biosensors to water treatment

The project aims to develop nanofluidic diodes using solid-state nanopore membranes and demonstrate their use for bio-sensing and ion separation applications. It builds on a versatile platform we developed to fabricate nanopores in thin SiO2 and Si3N4 membranes using ion track technology. This technology allows the controlled engineering of pores with defined shapes and sizes down to a few nanometres. At these dimensions, the pore opening becomes comparable to the Debye length, and the transport of molecules and ions through the pores becomes critically dependent on the surface charges of the pore-material. By integrating materials such as HfO2 and Al2O3 it is possible to locally tune these surface charges, resulting in interesting transport properties through the pores including pH-dependent ionic current rectification, pore-gating and ion-specific selectivity. Pores with such properties form the building blocks for advanced nanofluidic devices. The project will include simulation of the nanopore-properties, as well as design, fabrication and characterisation of the nanopore membranes, including demonstration of their application for sensing or ion separation. The fabrication tools used are compatible with semiconductor processes and allow integration of the pores into microelectronic components.