Berlin 2018 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 7: Biomaterials and Biopolymers (joint session BP/CPP)

CPP 7.4: Talk

Monday, March 12, 2018, 10:15–10:30, H 1058

Flexoelectricity in bones — •Fabian Vasquez-Sancho^1,2, Amir Abdollahi³, Dragan Damjanovic⁴, and Gustau Catalan^1,5 — ¹Institut Catala de Nanociencia i Nanotecnologia, Barcelona, Catalunya — ²CICIMA, Universidad de Costa Rica, San Jose, Costa Rica — ³Laboratori de Calcul Numeric, Universitat Politecnica de Catalunya, Barcelona, Catalunya — ⁴Ecole Politechnique Federale de Lausanne (EPFL), Lausanne, Switzerland — ⁵Institut Catala de Recerca i Estudis Avançats (ICREA), Barcelona, Catalunya

Bones have been known to generate electricity under pressure since Fukada and Yasuda's seminal measurement of bone piezoelectricity in 1957. This piezoelectricity is thought to be essential for bone's self-repair and remodelling properties, and its origin is attributed to the piezoelectricity of collagen (the main structural protein of bones). However, since the discovery of flexoelectricity, it is known that strain gradients can also generate voltages in materials of any symmetry. Here we have detected and quantified the flexoelectricity of bone and bone mineral (hydroxyapatite), and determined that flexoelectricity can account for bone's electrical response to inhomogeneous deformations. In addition, we have used the flexoelectric coefficient of hydroxyapatite to calculate the (flexo)electric fields generated by cracks in bone mineral. Crack-generated electricity has been found to be large enough to be able to induce osteocyte apoptosis and thus initiate the crack-healing process, indicating a central role of flexoelectricity in bone damage repair and remodelling.