Electrical properties of human bone as an electret

We analyzed the electrical properties of human bone in comparison with the electrically polarized and nonpolarized bone specimens and discussed the role of an organic and inorganic matrix of bone in bone piezoelectricity. Femoral neck bone was scanned to evaluate the cancellous bone structures using micro-computed tomography, and we quantified the carbonic acid by attenuated total reflection spectra to estimate carbonate apatite. The stored electrical charge in the electrically polarized and nonpolarized bone specimens were calculated using thermally stimulated depolarized current (TSDC) measurements. Each TSDC curve had 3 peaks at 100°C, 300°C and 500°C, which may be attributed to collagen, carbonate apatite and hydroxyapatite, respectively. It is suggested that organic substances are more effectively electrically polarized than apatite minerals and that the stored charge in bone may be affected by total bone mass and bone quality, including 3-dimensional structure and structural composition. (Received Jun 30, 2019; Accepted Jul 25,2019)