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Research Areas

The field of biological and bioinspired materials is continuously growing as the demand for smart and multifunctional materials continues to increase. Biological materials such as bones and shells as well as biological glues and brilliantly colored animal skin are fascinating and often multifunctional. Studying these materials can provide insights into structure-function relationships and thus provide important clues for smart design of bioinspired materials. In our group, we do basic research to understand specific biological materials as well as utilizing this understanding to produce new bioinspired materials in the lab as detailed below. 


Biological materials

The functionality of many biological materials is derived not only from the chemistry of the material, but even more so from its structure that ranges across length scales from the molecular to the anatomic. We work to elucidate these structure-function relationships in selected mineralized materials such as bone. We do this taking a multimodal approach, mostly focused on X-ray imaging.

Moreover, we collaborate with medical doctors and research groups around the world in a highly interdisciplinary manner to obtain the broadest possible understanding of these complex materials in health and disease. 

Research tools

  • X-ray imaging (absorption, phase, XRF, XRD) within AXIA and at synchrotrons
  • Electron microscopy
  • Optical microscopy
  • Raman spectroscopy
  • Nanoindentation and other mechanical tests

Projects

  • Understand structure-function relationships in different types of bones and shells
  • Identify structural patterns at the nano- and microscale
  • Elucidate biomineralization processes in different models
  • Understand the roles of the cellular network embedded within bone and how it affects the structure of the surrounding bone matrix
  • We further use our expertise within characterization of complex materials to study synthetic materials such as energy materials and catalysts in collaboration with other research groups and institutions. 

The individual student projects can be made more or less heavy on the data analysis side which is mainly performed with Matlab programming.

Bioinspired materials

The demand for smart, multifunctional, and/or adaptive materials is increasing, but the design and fabrication of such materials by traditional methods is difficult. Nature, however, has already devised solutions to many of the challenges faced by materials scientists, and can provide useful insights to materials design. In our group we are inspired by natural systems such as blue mussel glue to make synthetic adhesives that are both self-healing and works under water based on hydrogels and coacervates. In another project, we do crystallization of guanine for use in stimuli-responsive reflector materials inspired by the natural color-changing systems found in animals such as chameleons and copepods. 

Research tools

  • Material formulation, synthesis, and crystallization
  • Various characterization techniques including spectroscopy, microscopy, crystallography, and rheology

Projects

  • Development of bioinspired adhesives based on hydrogels and coacervates
  • Understand specific and non-specific interactions between polymers and metal ions
  • Crystallization of guanine for use in bioinspired stimuli-responsive reflectors

The individual student project can be tailored towards more or less lab and synthesis work or materials characterization and data analysis. 

X-ray imaging

A central characterization tool in our research is X-ray imaging. As X-rays are characterized by high penetration power and wavelengths at the Angstrom level, they are ideally suited for characterization of extended and mineralized samples across length scales ranging from the atomic to the anatomic depending on the imaging mode. The past decade has carried a massive technical development benefitting the development of these techniques, not only at large scale facilities (synchrotrons), but also in laboratory instruments. This has allowed for extension of classical (absorption-based) computed tomography to computed tomography with contrast from e.g. XRD or XRF. We are heavily involved with the development of these methods as well as writing of software (MultiRef) that can handle the enormous data sets that are generated. 

Method development

  • Multimodal X-ray characterization ranging from ultra-high resolution experiments at the synchrotron through in-house laboratory measurements (AXIA) to clinical experiments (the latter through collaboration with medical doctors)
  • X-ray imaging (2D and 3D) with advanced contrast mechanisms at synchrotron beamlines around the world
  • Data analysis software development in Matlab

Facilities

  • Henrik Birkedal is the main actor behind the Aarhus X-ray Imaging Alliance (AXIA)
  • Henrik Birkedal is part of the DanMAX consortium. DanMAX is a Danish materials science beamline at the new MAX IV synchrotron in Lund. 
  • The group is part of the ESS lighthouses on hard materials in 3D (SOLID) and Structure of Materials in Real Time (SMART).