PhD defence

Simpler, Faster, and Softer. Towards broad application of Laser Speckle Imaging in art conservation and soft matter


Most daily-use materials are not transparent, and thus hard to study with conventional optical imaging techniques. Laser Speckle Imaging (LSI) visualizes nanoscopic motion inside non-transparent materials and gives unique insights into material properties and their inner workings. We have developed an algorithm that allows quantitative LSI to be performed in real-time, allowing live imaging, and used this with a portable set-up. We successfully explored applications in art conservation, where we focus on the removal of varnish from oil paintings. Excess cleaning solvent will penetrate into the paint layer where it has undesirable effects. LSI can measure the motion of pigment particles as result of solvent presence in the paint, allowing conservators to stop solvent application at exactly the right moment. We also studied the syneresis process, where water is expulsed
from products like yoghurt and mayonnaise, and develop a method to simultaneously combine LSI results with bulk rheology measurements.