Ferroelectricity and piezoelectricity in soft biological tissue

Ferroelectricity and piezoelectricity in soft biological tissue: Porcine aortic walls revisited

Lenz, Thomas (Max Planck Institute for Polymer Research; Graduate School Materials Science in Mainz)
Hummel, Regina (Johannes Gutenberg-University Mainz)
Katsouras, Ilias (TNO)
Groen, W.A. (TU Delft Novel Aerospace Materials; TNO)
Nijemeisland, M. (TU Delft Delft Aerospace Structures and Materials Laboratory)
Ruemmler, Robert (Johannes Gutenberg-University Mainz)
Schäfer, Michael K.E. (Johannes Gutenberg-University Mainz)
de Leeuw, D.M. (TU Delft Novel Aerospace Materials; Max Planck Institute for Polymer Research)

2017-09-25

Recently reported piezoresponse force microscopy (PFM) measurements have proposed that porcine aortic walls are ferroelectric. This finding may have great implications for understanding biophysical properties of cardiovascular diseases such as arteriosclerosis. However, the complex anatomical structure of the aortic wall with different extracellular matrices appears unlikely to be ferroelectric. The reason is that a prerequisite for ferroelectricity, which is the spontaneous switching of the polarization, is a polar crystal structure of the material. Although the PFM measurements were performed locally, the phase-voltage hysteresis loops could be reproduced at different positions on the tissue, suggesting that the whole aorta is ferroelectric. To corroborate this hypothesis, we analyzed entire pieces of porcine aorta globally, both with electrical and electromechanical measurements. We show that there is no hysteresis in the electric displacement as well as in the longitudinal strain as a function of applied electric field and that the strain depends on the electric field squared. By using the experimentally determined quasi-static permittivity and Young's modulus of the fixated aorta, we show that the strain can quantitatively be explained by Maxwell stress and electrostriction, meaning that the aortic wall is neither piezoelectric nor ferroelectric, but behaves as a regular dielectric material.

http://resolver.tudelft.nl/uuid:12e1f4d8-7cff-4383-ba4a-6cca9a07e4a5

https://doi.org/10.1063/1.4998228

2018-10-01

0003-6951

Applied Physics Letters, 111 (13)

Institutional Repository

journal article

© 2017 Thomas Lenz, Regina Hummel, Ilias Katsouras, W.A. Groen, M. Nijemeisland, Robert Ruemmler, Michael K.E. Schäfer, D.M. de Leeuw