High resolution microscopy techniques have revolutionised the imaging of nanoscopic structures in the biological field. We want to apply this concept to polymeric materials to study the nanoscopic origins of fracture and failure in polymers, such as cavity formation, crack formation, and propagation. To achieve this, we are developing new classes of molecular mechano-probes. When incorporated in polymer chains, these probes give out an optical signal when a force is applied to them that can be monitored with fluorescence microscopy. This will allow us to not only image the nanostructure of polymers but also make maps of local properties within the material.