title: Biological ferroelectricity uncovered in aortic walls by piezoresponse force microscopy.
abstract: Many biological tissues are piezoelectric and pyroelectric with spontaneous polarization. Ferroelectricity, however, has not been reported in soft biological tissues yet. Using piezoresponse force microscopy, we discover that the porcine aortic walls are not only piezoelectric, but also ferroelectric, with the piezoelectric coefficient in the order of 1 pm/V and coercive voltage approximately 10 V. Through detailed switching spectroscopy mapping and relaxation studies, we also find that the polarization of the aortic walls is internally biased outward, and the inward polarization switched by a negative voltage is unstable, reversing spontaneously to the more stable outward orientation shortly after the switching voltage is removed. The discovery of ferroelectricity in soft biological tissues adds an important dimension to their biophysical properties, and could have physiological implications as well.
authors.affiliation: Department of Mechanical Engineering, University of Washington, Seattle, Washington 98195, USA.
authors.forename: Yuanming
authors.initials: Y
authors.lastname: Liu
authors.forename: Yanhang
authors.initials: Y
authors.lastname: Zhang
authors.forename: Ming-Jay
authors.initials: MJ
authors.lastname: Chow
authors.forename: Qian Nataly
authors.initials: QN
authors.lastname: Chen
authors.forename: Jiangyu
authors.initials: J
authors.lastname: Li
mesh_terms: D000818:Animals; D001011:Aorta / Q000648:ultrastructure*; D004560:Electricity; D004563:Electrochemistry; D005290:Ferric Compounds / Q000737:chemistry*; D008422:Materials Testing; D018625:Microscopy, Atomic Force; D013552:Swine
chemical_list: D005290:Ferric Compounds