Capture structures without looking at them directly, but rather by probing their interaction with electromagnetic waves - this is the basic principle for the new multi-modal tensor tomography developed in this research project. It enables to study the arrangement of nanostructures in macroscopic samples, six orders of magnitude larger than its building blocks. In a standard computed tomography (CT) the inside of three-dimensional objects or the human body can be routinely studied, providing a grey-scale map of electron density in each sub-volume, called voxel. Compared to this scalar value (i.e. grey scale), with tensor tomography we can extract much more information in each voxel, in particular the three-dimensional orientation of the local nanostructure. Different modes of tensor tomography are explored within this project, using visible light and X-rays. An open-source software package is being developed, with the aim of making the developed methods available to the scientific community. Over the interaction of X-rays with the sample not only orientations can be obtained, but also size and shape can be retrieved for which we work on new algorithms to extract all information contained, including the exploration of coherence within this method. With visible light the orientation of ultrastructures, i.e. structures which are smaller than what can be resolved with traditional light microscopy, can be probed with the change in polarization state. Within MUMOTT we are combining this approach with tensor tomography, in order to investigate the local structure spatially resolved in three-dimensional samples.
Apart from the methodology framework we are implementing the different modes to prove their capability in different application examples in materials and bio-science. This will serve to received significant attention in the relevant scientific communities, which will stimulate the future use of the methods being developed. As examples of material science application, we will investigate the structure of fiber composites and s reveal how the arrangement of nanoparticles in a plasmonic composite is connected to its sensing capabilities. In bio-science we are focusing on the extra-cellular matrix, in particular collagen, and how it is changing in pathological cases. Concretely we study the disruptive collagen network in liver fibrosis and changes in the extracellular matrix in connection to metastatic breast cancer.
