The VSMM will probe the local reflection and transmission microwave spectroscopy of key materials properties, measuring complex permittivity, conductivity, resistivity, and magnetic response, and hence structural and chemical material constitution with 3D nanoscale resolution. The work will address the technical development of the tool and demonstrate its ability to characterise the 3D structure in situ at the nanoscale. The tool will be applied to relevant real-life systems including nanoparticle drug uptake in biological cells, domain structure in ferroelectric devices and trap mechanisms in solar cells. The system will be designed to allow ease of use through dedicated work-flows and will include intuitive real time visualisation for results optimisation and processing. Methods for calibration and provision of traceability are incorporated into the project from the start: this will ensure that VSMM measurements will be quantitatively meaningful and optimised for accuracy and will ensure the most efficient route to commercialisation and uptake of the VSMM. The fact that the VSMM will utilise SPM cantilever-probe technology will ensure that it is readily compatible with a full range of other SPM-based tools – opening up its future role in integrated multi-physical materials characterisation at the nanoscale.