Researchers discover why tendons are strong as wire ropes
Under the electron microscope: collagen fiber bundle after mineralization with (the bone mineral) calcium phosphate. © Max-Planck-Institut für Kolloid- und Grenzflächenforschung
A team at the Max Planck Institute of Colloids and Interfaces (MPICI) has discovered with help of BESSY II new properties of collagen: During the intercalation of minerals in collagen fibers, a contraction tension is generated that is hundreds of times stronger than muscle strength. The associated changes in the collagen structure were observed using X-ray diffraction at the BESSY II synchrotron in Berlin-Adlershof while mineralization was taking place.
"This universal mechanism of mineralization of organic fiber tissues could be transferred to technical hybrid materials, for example, to achieve high breaking strength there," says Prof. Dr. Dr.h.c. Peter Fratzl, Director at the institute.
The fiber-forming structural protein collagen is found in tendons, skin and bones, among other places. It is also interesting from a medical or biological point of view to understand what happens in the process of mineralization in bones. Many bone diseases are associated with changes in mineral content in bones and thus altered properties.
Read the full press release on the MPIKG website.
- Magnetic imaging: Micro-flowers increase the local magnetic fieldMaterials with magnetic nanostructures have many potential applications such as in spintronics. To explore such materials, nanoscale magnetic-sensitive imaging techniques are very useful, but up to now only weak magnetic fields could be applied during the imaging process. Now an international collaboration led by Dr. Sergio Valencia, HZB, has developed an approach that overcomes this limitation. The team designed tiny magnetic flux concentrators (MFCs), into which the sample is placed. The geometry of the MFCs resembles a flower with a number of petals which focus the applied magnetic field into its center. This greatly expands the magnetic field range available during imaging, and so the range of magnetic systems that can be investigated. The micro-flowers, enhancing magnetic fields locally, can find application in different nanometric magnetic microscopy techniques.
- Disorder creates new properties in compound semiconductorsAn international research team has demonstrated that the intrinsic disorder of the compound semiconductor CuInSnS₄ can be exploited to influence its optical properties. While the atomic vibrations also sense the local disorder, their response is averaged over many different local environments and therefore appear isotropic, as expected for a cubic crystal. In contrast, the optical excitations, known as excitons, are much more sensitive to the local arrangement of atoms. Surprisingly, they show a direction-dependent optical response even though the average crystal structure is cubic. These findings shed new light on the relationship between disorder and material properties, opening up new options for targeted 'disorder engineering' in optoelectronic and photocatalytic devices.
- Superconducting TES array X-ray spectrometer goes into operation at BESSY IIEurope's first and only TES-spectrometer at a synchrotron source is now in operation at BESSY II, developed within a collaboration between the HZB, the MPI-CEC (Mühlheim-an-der-Ruhr, Germany) and the NIST (Boulder CO, USA). The photon detection efficiency of the new instrument exceeds that of wavelength-dispersive X-ray emission spectrometers by a factor of 100 to 1000. It will be used to investigate the electronic properties of atomically thin layers, nanostructures and highly diluted atomic and molecular samples. The team is looking forward to receiving exciting research proposals from the user community.