In the field of nano-optics, the Van der Waals (VdWs) material α-MoO3 can host directional phonon-polaritons (PhPs) with in-plane propagation owing to its highly anisotropic crystalline structure, which finds very interesting applications for light-matter interactions. In this regard, both developing practical strategies to introduce controlled strain fields in nanomaterials to reversibly vary their crystalline structure (i.e., in-plane propagation direction of the polaritons in α-MoO3) and a precise quantification of the strain field in terms of magnitude and anisotropy are fundamental. In this proposal, we aim the in-situ measurement of changes in the crystalline structure of thin α-MoO3 crystals (thicknesses from about 50 nm to 100 nm) induced by strain fields introduced in the crystals employing hybrid VdWs-piezoelectric devices. For that we propose to measure Laue diffraction patterns at the micro-Laue setup of BM32.