Abstract
X-ray Imaging for Characterizing Structure-Function in 4D: From Spiders to Sharks
Getting insights into the structure and function of biological and bioinspired materials under realistic
conditions is key to advancing their design. At the beamline P05 at PETRA III (DESY, Hamburg), operated by
Helmholtz-Zentrum Hereon, full-field hard X-ray nanotomography enables non-destructive 3D imaging.
Spatial resolutions down to 40 nm and scan times of less than one minute per 3D volume, offer ideal
conditions for in situ experiments, like mechanical testing. For low attenuating biological materials, phase
contrast methods are especially suitable, including transmission X-ray microscopy (TXM) with Zernike phase
contrast, and cone-beam holotomography.
Here the variability of these nanotomography methods and techniques is demonstrated, showcasing in situ
mechanical studies on spider attachment hairs and shark cartilage, shrinking and swelling of wood cells,
performance of biodegradable implants, and imbibition of hierarchically porous silica. These experiments
reveal how structural hierarchy changes under mechanical load, hydration and degradation processes. The
ability to visualize internal transformation, triggered for example by water uptake, provides critical insights
into the structure–function relationship and supports the development of responsive, bioinspired systems.
The nanotomography instrument at the beamline P05 thus offers a unique platform for 4D characterization,
capturing not only the structure but also the temporal evolution of materials, bridging biology, medicine, and
engineering.