Rapid fabrication of nanoporous membrane arrays and single-pore membranes from parylene C

Abstract

We report the fabrication of highly ordered arrays of uniformly sized nanopores from polymer vapor deposition and extend this straightforward approach to the production of single-pore membranes. The fabrication protocol for single-pore membranes and porous membrane arrays (PMAs) offers precise control over pore size and can be readily tailored for batch fabrication. PMAs were utilized as templates to construct both epoxy resin and silica micro/nanostructures that replicate pore geometries. As established from silica micro/nanostructures and electron microscopy, pore sizes were tuned from tens of micrometers to as low as ∼100 nm for PMAs and 40 nm for single-pore membranes. Ion transport of redox molecules and non-redox active ions through hydrophobic porous membranes was investigated with scanning electrochemical microscopy (SECM) and scanning ion conductance microscopy (SICM), respectively. In addition, the application of PMAs toward spatial patterning of polystyrene microspheres deposited from a colloidal solution onto the membrane surface was demonstrated. This research identifies a unique strategy in nanopore fabrication. The method described to produce PMAs provides an effective and inexpensive process for production of a well-ordered three-dimensional architecture that typically requires complex instrumentation, elaborate lithographic procedures or lengthy processing techniques.