This project aims to develop a method for detecting changes in the nano-architecture of thin film membranes used in liquid phase separation processes. It builds on recent advances in Electrical Impedance Spectroscopy (EIS) techniques that generate information on the electrical properties across the thin film in situ and in real time. These new techniques to generate and interpret EIS spectra will provide insight, at the nano-scale, into changes (such as engineered surface modifications or fouling) that impact the functionality and performance of polymeric membranes. This will lead to new instrumentation that can be used to improve the performance of industrially important membrane processes such as reverse osmosis and nano-filtration and provide researchers with a tool for rapid screening and characterisation of advanced separation processes such as forward osmosis (FO) and piezoelectric membranes (PEM).