Piezoelectric properties of synthetic hydroxyapatite-based organic-inorganic hydrated materials

Disks of synthetic hydroxyapatite agglutinated with a synthetic polymer and hydrated in a moisture fog, were prepared. A well-defined piezoelectric signal of these samples was obtained when a relative small compression stress of 35 MPa (corresponding a force of 450 daN) was applied; piezoelectric signals of up to 12 mV were obtained with this stress. Two different compression methods were followed to obtain the piezoelectric signal: (a) hold method, where the load was maintained constant once it reaches the maximum stress and (b) release method, where the load was removed rapidly when the stress reaches its maximum value. The samples were characterized using the techniques: X-ray Diffraction, Dielectric Relaxation Spectroscopy and mechanical test. (C) 2016 The Authors. Published by Elsevier B.V.