Defects in crystals have a critical influence on the propertie of nanocrystals, where a single defect can completely change the properties. Due to the proximity of surfaces, the energy and mobility of defects in nano-objects are borne to be very different from that of the bulk. We propose to perform in-situ nano-indentation experiments, using a custom-built AFM, on single twinned Au crystals coupled with multi-Bragg Coherent X-ray diffraction Imaging (BCDI), simultaneously measuring symmetric as well as asymmetric Bragg peaks that are sensitive to the different parts of the twinned crystal. The planned in-situ BCDI measurements will allow for directly visualizing the influence of the twin boundary acting as dislocation source/sink or more or less permeable barrier.