Parts | Days | Selection | Search | Updates | Downloads | Help

MM: Fachverband Metall- und Materialphysik

MM 64: Topical session: X-ray and neutron scattering in materials science V - X-ray Nanodiffraction Characterization of Inhomogeneous Structural and Mechanical Properties of Thin Films

MM 64.4: Talk

Friday, April 4, 2014, 11:15–11:30, BAR 205

Investigation of the piezoelectric behaviour in bones on a micrometer length scale — •D.C.F. Wieland¹, D. Kluess², E. Mick², C. Krywka¹, R. Willumeit¹, and R. Bader² — ¹Helmholtz-Zentrum Geesthacht, Institut für Werkstoffforschung, Max-Planck-Straße 1, 21502 Geesthacht, Germany — ²Universitätsmedizin Rostock, Orthopädische Klinik und Poliklinik, 18057 Rostock, Germany

Electromagnetic stimulation is a clinical treatment for improving bone healing e.g. in the femoral head in case of avascular necrosis. It is supposed to be based on the principle of a reciprocal piezoelectric effect in combination with piezoelectric properties of bone tissue. Therefore, we have investigated the structure of bone at different applied voltages by means of micro diffraction at the nanofocus endstation of the P03., PETRA III, Germany. Slices of 150 *m thickness were cut from bovine trabecular bone and placed between two clamps designed to apply AC current on the sample. In order to extract the structure of the bone matrix at different positions with high resolution, the samples were scanned by a X-ray beam with the size of 1.5 *m. Each position was scanned over an array of 30 x 30 points within an area of 45 x 45 *m. To determine the effect of voltage applied at the bone samples, the measurements were repeated at 0V, 5V and 10V. Our data hints that the hydroxyapatite crystals in the bone matrix, which amount 65% of the bone mass are subject to mechanical stress if the applied voltage is increased from 0 to 10V. Furthermore, this effect depends strongly on the orientation of collagen fibrils in the bone matrix. Other properties of the hydroxyapatite like the orientation of the crystals are unaffected.