Accession Number : ADA621919


Title :   Flexoelectricity in PZT Nanoribbons and Biomembranes


Descriptive Note : Final rept. 1 Oct 2011-30 Sep 2014


Corporate Author : PENNSYLVANIA UNIV PHILADELPHIA


Personal Author(s) : Purohit, Prashant K


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a621919.pdf


Report Date : 09 Jan 2015


Pagination or Media Count : 8


Abstract : The objective of this grant was to study flexoelectric phenomena in solids and in biomembranes. Over a three year period funds from this grant were used to accomplish several projects that form a large part of the PhD thesis of Mr. Sheng Mao. In the first project we formulated the governing equations for a flexolelectric solid undergoing small deformations. These governing equations were used to solve for the stress, displacement and polarization fields in several one and two-dimensional electromechanical problems. A key highlight of this paper was a flexoelectric reciprocal theorem. We used the formulation in this paper to solve for the electrical and mechanical fields around point defects, dislocations and cracks in flexoelectric solids. We confirmed the important role of flexoelectricity in the immediate vicinity of defects due to the existence of large strain gradients. A key highlight of this paper was that we showed that flexoelectricity is the most likely mechanism behind electromagnetic radiation from moving dislocations and cracks in ice. We also collaborated with Michael McAlpine in Princeton on several projects. We studied the electromechanical response of neuronal cells, energy harvesting using pyro-para-electricity and a new way of producing PZT nanoribbons for energy harvesters.


Descriptors :   *ELECTROMECHANICAL DEVICES , *MEMBRANES(BIOLOGY) , *NANOTECHNOLOGY , *NERVE CELLS , *POLYMERIZATION , *PYROELECTRICITY , CELLS(BIOLOGY) , CRACKS , DEFECTS(MATERIALS) , DEFORMATION , DISLOCATIONS , DISPLACEMENT , ELECTRICAL CONDUCTIVITY , ELECTRICAL PROPERTIES , ELECTROMAGNETIC RADIATION , ENERGY HARVESTING , FREQUENCY RESPONSE , LEAD ZIRCONATE TITANATES , MECHANICAL PROPERTIES , POLARIZATION , PRESSURE GRADIENTS , STRAIN(MECHANICS) , STRESSES , THIN FILMS


Subject Categories : Physical Chemistry
      Electrical and Electronic Equipment
      Solid State Physics
      Biomedical Instrumentation and Bioengineering


Distribution Statement : APPROVED FOR PUBLIC RELEASE