Here we propose a study that will contribute to the final challenges of PhD training programme (Emma Palin). We will study the electrochemical dissolution of a bi-metallic films using event-mode NR methods. We have recently established a novel, environmentally sustainable methodology for deposition of multi-layer metal films using non-toxic DES solvents. The purpose of our study here is to measure and understand the behaviour of these films in DES media and to determine if there is any mixing of the metal layers at the interface where they meet. These questions are very important to the manufacture and stability of devices that use printed circuit boards because the metal tracks that connect components are fabricated from several layers of metal. Where mixing of metals occurs, the assemblies can become brittle and fragile. This results in damage if the device is dropped or shocked.