DOCSLIB.ORG

Two-Dimensional Ferroelectrics

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Two-Dimensional Ferroelectrics University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Stephen Ducharme Publications Research Papers in Physics and Astronomy 2000 Two-Dimensional Ferroelectrics L. M. Blinov Institute of Crystallography, Russian Academy of Sciences, Leninski|¯ prosp. 59, 117333 Moscow, Russian Federation V. M. Fridkin Institute of Crystallography, Russian Academy of Sciences, Leninski|¯ prosp. 59, 117333 Moscow, Russian Federation S.P. Palto Institute of Crystallography, Russian Academy of Sciences, Leninski|¯ prosp. 59, 117333 Moscow, Russian Federation A. V. Bune University of Nebraska - Lincoln Peter A. Dowben University of Nebraska-Lincoln, [email protected] See next page for additional authors Follow this and additional works at: https://digitalcommons.unl.edu/physicsducharme Part of the Physics Commons Blinov, L. M.; Fridkin, V. M.; Palto, S.P.; Bune, A. V.; Dowben, Peter A.; and Ducharme, Stephen, "Two- Dimensional Ferroelectrics" (2000). Stephen Ducharme Publications. 51. https://digitalcommons.unl.edu/physicsducharme/51 This Article is brought to you for free and open access by the Research Papers in Physics and Astronomy at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Stephen Ducharme Publications by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Authors L. M. Blinov, V. M. Fridkin, S.P. Palto, A. V. Bune, Peter A. Dowben, and Stephen Ducharme This article is available at DigitalCommons@University of Nebraska - Lincoln: https://digitalcommons.unl.edu/ physicsducharme/51 Physics ± Uspekhi 43 (3) 243 ± 257 (2000) # 2000 Uspekhi Fizicheskikh Nauk, Russian Academy of Sciences REVIEWS OF TOPICAL PROBLEMS PACS numbers: 75.70. ± i, 77.80. ± e Two-dimensional ferroelectrics L M Blinov, V M Fridkin, S P Palto, A V Bune, P A Dowben, S Ducharme DOI: 10.1070/PU2000v043n03ABEH000639 Contents 1. Introduction 243 2. Ferroelectricity and the ferroelectric phase transitions 244 3. Thin ferroelectric films and the finite-size effect 245 4. Ferroelectric polymers: vinylidene fluoride copolymers 247 5. Langmuir ± Blodgett ferroelectric films 249 6. Two-dimensional ferroelectric films 254 7. The surface phase transition in ferroelectric films 256 8. Conclusions 256 References 257 Abstract. The investigation of the finite-size effect in ferroelec- 1. Introduction tric crystals and films has been limited by the experimental conditions. The smallest demonstrated ferroelectric crystals Ultrathin crystalline films offer the possibility of exploring had a diameter of 200 A and the thinnest ferroelectric films phase transitions in the crossover region between two and were 200 A thick, macroscopic sizes on an atomic scale. three dimensions. Second-order ferromagnetic phase transi- Langmuir ± Blodgett deposition of films one monolayer at a tions have been observed in monolayer magnetic films [1, 2], time has produced high quality ferroelectric films as thin as where the surface anisotropy energy stabilizes the two- 10 A, made from polyvinylidene fluoride and its copolymers. dimensional ferromagnetic state at finite temperatures [3]. These ultrathin films permitted the ultimate investigation of Similarly, a number of magnetic materials have magnetic finite-size effects on the atomic thickness scale. Langmuir ± surface layers that show a second-order ferromagnetic ± Blodgett films also revealed the fundamental two-dimensional paramagnetic phase transition with an increased Curie character of ferroelectricity in these materials by demonstrat- temperature [4]. Ferroelectricity is in many ways analogous ing that there is no so-called critical thickness; films as thin as to ferromagnetism, and bulk ferroelectricity and finite-size two monolayers (1 nm) are ferroelectric, with a transition effects have been observed in nanocrystals as small as temperature near that of the bulk material. The films exhibit 200 A in diameter [5, 6], and in thin films as thin as 600 A all the main properties of ferroelectricity with a first-order [7] {. First-order ferroelectric ± paraelectric phase transitions ferroelectric ± paraelectric phase transition: polarization hys- in surface layers approximately 200 A thick have been teresis (switching); the jump in spontaneous polarization at the reported by Scott et al. [8] and found to have enhanced phase transition temperature; thermal hysteresis in the polar- transition temperatures. These results also can be interpreted ization; the increase in the transition temperature with applied as bulk ferroelectricity suppressed by the effects of surface field; double hysteresis above the phase transition temperature; energy and the depolarization field, and imply that the bulk and the existence of the ferroelectric critical point. The films ferroelectric state is associated with a minimum critical size also exhibit a new phase transition associated with the two- [8 ± 10]. Nevertheless, it is clear that the ferroelectric phase dimensional layers. transition in the two-dimensional lattice is possible even in the simplest two-dimensional Ising model, as shown by Onsager in 1944 [11]. L M Blinov, V M Fridkin, S P Palto Institute of Crystallography, Russian Academy of Sciences, Here, we present a review of investigations of the ferro- Leninski|¯ prosp. 59, 117333 Moscow, Russian Federation electric phase transition in crystalline films of a random Tel. (7-095) 135 15 00. Fax (7-095) 135 10 11 copolymer of vinylidene fluoride and trifluoroethylene as E-mail: [email protected] thin as 10 A (two monolayers) prepared by Langmuir ± A V Bune, P A Dowben, S Ducharme Department of Physics and Blodgett (LB) deposition. The first-order ferroelectric phase Astronomy, Behlen Laboratory of Physics, Center for Materials Research transition with a Curie temperature nearly equal to the bulk and Analysis, University of Nebraska ± Lincoln, value was observed even in these essentially two-dimensional Lincoln, NE 68588-0111, USA Tel. 402-472-8590. Fax 402-472-2879 films. In addition, we observed a second phase transition at a E-mail: [email protected] lower temperature, which seems to have a surface nature. The absence of finite-size effects on the bulk transition implies Received 8 August 1999 Uspekhi Fizicheskikh Nauk 170 (3) 247 ± 262 (2000) Translated by V M Fridkin; edited by S N Gorin { And possibly as thin as 100 A, see Karasawa J et al. Integrated Ferroelectrics 12 105 (1996). (Authors' note for English Edition.) 244 L M Blinov, V M Fridkin, S P Palto, A V Bune, P A Dowben, S Ducharme Physics ± Uspekhi 43 (3) that these films must be considered as two-dimensional The equilibrium temperature of transition from para- ferroelectrics. electric to ferroelectric phase is Tc T0; all properties are dependent on the difference between the crystal temperature 2. Ferroelectricity and the ferroelectric phase T and the phase transition temperature Tc. The Æ signs transitions indicate that the polarization can point in either direction along the symmetry axis (recall that this is the uniaxial Ferroelectric materials have fascinated scientists since their case), and correspond to the two energetically equivalent discovery in 1920 [12 ± 15]. In analogy with ferromagnets, the states of the ferroelectric crystal at zero electric field. characteristic properties of ferroelectrics include spontaneous Equation (2.4) shows the typical result that at the second- electric polarization, polarization reversal (switching), and order ferroelectric phase transition there is no jump in the disappearance of the polarization above a ferroelectric phase order parameter (the magnitude Ps in this case) and in the transition temperature Tc. Ferroelectric materials have been a latent heat of transition. However, there is a jump in the fertile field for the study of phase transitions, electron ± heat capacity. phonon interactions, polaritons, and other optical and The dielectric polarizability w in the paraelectric phase is electrical phenomena in condensed matter. built-in to the definition of a and calculated from the free From the time of the first reports of Valasek in the early energy density expansion (2.1) and equilibrium conditions 1920s [12, 16], many books and reviews have been devoted to (2.2): the problem of ferroelectricity [14, 15, 17 ± 19]. V L Ginzburg q2F 1 T T developed the first phenomenological theory of ferroelectri- 0 : 2 city in the 1940s [20, 21] based on the Landau theory of qP w e0C second-order phase transitions [22 ± 24] and a similar treat- ment was developed by Devonshire shortly thereafter [13, 25, The dielectric constant of the medium e e1 w=e0 26]. Later, many phenomenological aspects of the problem contains contributions from the background polarizability were developed by E M Lifshitz, V L Ginzburg, A P Levanyuk, and the ferroelectric polarizability (2.5). D G Sannikov, V L Indenbom, and others. Here, we are The general first-order phase transition is accompanied by giving only a short summary of the Landau ± Ginzburg a small but finite jump of the order parameter P and enthalpy. phenomenological treatment of the ferroelectric phase transi- Many ferroelectric materials exhibit a special kind of first- tions. order phase transition with a change of symmetry from a Presuming that the order parameter in the Landau theory group to subgroup, which is close to the situation in the has the same transformation properties as the polarization second-order transition, and can be described by the free- vector P, we can in the uniaxial case express the Gibbs free
Load more

Recommended publications
  • Ferroelectric Polymer Networks with High Energy Density and Improved Discharged Efficiency for Dielectric Energy Storage
    ARTICLE Received 12 Aug 2013 | Accepted 29 Oct 2013 | Published 26 Nov 2013 DOI: 10.1038/ncomms3845 Ferroelectric polymer networks with high energy density and improved discharged efficiency for dielectric energy storage Paisan Khanchaitit1,w, Kuo Han1, Matthew R. Gadinski1,QiLi1 & Qing Wang1 Ferroelectric polymers are being actively explored as dielectric materials for electrical energy storage applications. However, their high dielectric constants and outstanding energy densities are accompanied by large dielectric loss due to ferroelectric hysteresis and electrical conduction, resulting in poor charge–discharge efficiencies under high electric fields. To address this long-standing problem, here we report the ferroelectric polymer networks exhibiting significantly reduced dielectric loss, superior polarization and greatly improved breakdown strength and reliability, while maintaining their fast discharge capability at a rate of microseconds. These concurrent improvements lead to unprecedented charge–discharge efficiencies and large values of the discharged energy density and also enable the operation of the ferroelectric polymers at elevated temperatures, which clearly outperforms the melt-extruded ferroelectric polymer films that represents the state of the art in dielectric polymers. The simplicity and scalability of the described method further suggest their potential for high energy density capacitors. 1 Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA. w Present address: National Science and Technology Development Agency, National Nanotechnology Center, Pathum Thani 12120, Thailand. Correspondence and requests for materials should be addressed to Q.W. (email: [email protected]). NATURE COMMUNICATIONS | 4:2845 | DOI: 10.1038/ncomms3845 | www.nature.com/naturecommunications 1 & 2013 Macmillan Publishers Limited. All rights reserved.
    [Show full text]
  • PVDF and Its Copolymers Page 1 of 5
    PVDF and its Copolymers page 1 of 5 Properties of PVDF and its copolymers. PVDF is a semicrystalline polymer consisting of ferroelectric lamellar crystallites embedded in an amorphous dipolar matrix. Bulk PVDF is a mixture of crystalline and noncrystalline regions with a crystallinity of 50%. Its ferroelectricity was first proven by Furukawa et al. by demonstrating a hysteresis loop in the electric field dependence of the dielectric displacement, D(E). 1 The chemical structure of PVDF contains the repeat unit of doubly fluorinated ethane CH2-CF2. Each unit exhibits a dipole moment of 7×10-30 Cm associated with positively charged H-atoms opposing the negatively charged F-atoms. Since such dipoles are rigidly attached to main-chain carbons, their orientation is directly controlled by the conformation and packing of molecules. PVDF forms four polymorph crystalline phases that are defined by the conformation of the polymer chains and their steric order (crystalline structure). The most common crystalline phase is the α-phase made up of zigzag chains composed of carbon atoms aligned in the c-axis. This varying alignment of carbon atoms is expressed by the trans-gauche conformation (TGTG’, Figure 1). PVDF molecules in trans-gauche conformation have an antiparallel packing motif (see Figure 1) in order to relax the interactions of fluorine atoms in neighbouring chains, thus resulting in a non-polar semi-crystalline material. In the all-trans conformation (TTTT) the carbon chains are aligned in a more straight fashion (zigzag) as compared to the configuration of the α-phase. Here the CH2-CF2 dipoles are strictly oriented perpendicular to the chain axis (carbon nackbone).
    [Show full text]
  • Polarization Dynamics in Ferroelectric Thin Films
    MAX-PLANCK INSTITUTE FOR POLYMER RESEARCH JOHANNES GUTENBERG UNIVERSITY MAINZ DISSERTATION Polarization Dynamics in Ferroelectric Thin Films Written by Dong Zhao Supervised by Prof. Dr. Paul Blom (Max-Planck Institute for Polymer Research) Prof. Dr. Hans-Joachim Elmers (Institute of Physics, Johannes Guttenberg University Mainz) Declaration of Authorship I declare that I have written the enclosed PhD thesis by myself, and have not used sources or means without declaration in the text. Any thoughts from others or literal quotations are clearly marked. Signed: _______________________ Date: _________________________ Contents 1. Introduction 1.1. Fundamentals of ferroelectricity …………………………………………………….2 1.2. PVDF-based polymer ferroelectric thin films ……..………………………………..4 1.3. Motivation of the thesis ..…...…………………………………………………………..7 1.4. Outline of the thesis ......……………………………………………………………...11 2. Theory of polarization switching 2.1. Intrinsic and extrinsic switching ………………………………………………….14 2.2. Landau-Ginzburg-Devonshire theory ..…………………………………………….15 2.3. Monte-Carlo simulation ....………………………………………………………..18 2.4. Effects of disordered pinning sites ...…………………………………………….19 2.5. Summary ...………………………………………………………………………….23 3. Device fabrication and characterization 3.1. Spin-coated P(VDF-TrFE) thin films .....……………………………….……………25 3.2. Electrical measurements .....………………………………………………………….25 3.3. Piezoresponse force microscopy (PFM) ……………….…………………………30 4. Switching dynamics in disordered ferroelectric thin films 4.1. Kolmogorov-Avrami-Ishibashi (KAI)
    [Show full text]
  • Properties and Applications of Flexible Poly(Vinylidene Fluoride)-Based Piezoelectric Materials
    crystals Review Properties and Applications of Flexible Poly(Vinylidene Fluoride)-Based Piezoelectric Materials Linfang Xie 1, Guoliang Wang 1, Chao Jiang 2, Fapeng Yu 1,* and Xian Zhao 1,2,* 1 State Key Laboratory of Crystal Materials and Institute of Crystal Materials, Shandong University, Jinan 250100, China; [email protected] (L.X.); [email protected] (G.W.) 2 Key Laboratory of Laser & Infrared System, Ministry of Education, Shandong University, Qingdao 266237, China; [email protected] * Correspondence: [email protected] (F.Y.); [email protected] (X.Z.) Abstract: Poly (vinylidene fluoride) (PVDF) is a kind of semicrystalline organic polymer piezoelectric material. Adopting processes such as melting crystallization and solution casting, and undergoing post-treatment processes such as annealing, stretching, and polarization, PVDF films with high crystallinity and high piezoelectric response level can be realized. As a polymer material, PVDF shows excellent mechanical properties, chemical stability and biocompatibility, and is light in weight, easily prepared, which can be designed into miniaturized, chip-shaped and integrated devices. It has a wide range of applications in self-powered equipment such as sensors, nanogenerators and currently is a research hotspot for use as flexible wearable or implantable materials. This article mainly introduces the crystal structures, piezoelectric properties and their applications in flexible piezoelectric devices of PVDF materials. Keywords: poly(vinylidene fluoride); self-powered
    [Show full text]
  • Electroactive Polymers for Sensing
    Downloaded from http://rsfs.royalsocietypublishing.org/ on July 5, 2016 Electroactive polymers for sensing Tiesheng Wang1,2, Meisam Farajollahi3, Yeon Sik Choi1, I-Ting Lin1, Jean E. Marshall1, Noel M. Thompson1, Sohini Kar-Narayan1, rsfs.royalsocietypublishing.org John D. W. Madden3 and Stoyan K. Smoukov1 1Department of Materials Science and Metallurgy, University of Cambridge, Cambridge CB3 0FS, UK 2EPSRC Centre for Doctoral Training in Sensor Technologies and Applications, University of Cambridge, Cambridge CB2 3RA, UK Review 3Advanced Materials and Process Engineering Laboratory, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4 Cite this article: Wang T, Farajollahi M, Choi TW, 0000-0001-7587-7681; MF, 0000-0001-8605-2589; YSC, 0000-0003-3813-3442; YS, Lin I-T, Marshall JE, Thompson NM, I-TL, 0000-0001-9025-9611; JEM, 0000-0001-7617-4101; NMT, 0000-0002-9310-169X; Kar-Narayan S, Madden JDW, Smoukov SK. SK-N, 0000-0002-8151-1616; JDWM, 0000-0002-0014-4712; SKS, 0000-0003-1738-818X 2016 Electroactive polymers for sensing. Electromechanical coupling in electroactive polymers (EAPs) has been widely Interface Focus 6: 20160026. applied for actuation and is also being increasingly investigated for sensing http://dx.doi.org/10.1098/rsfs.2016.0026 chemical and mechanical stimuli. EAPs are a unique class of materials, with low-moduli high-strain capabilities and the ability to conform to surfaces One contribution of 8 to a theme issue of different shapes. These features make them attractive for applications such as wearable sensors and interfacing with soft tissues. Here, we review ‘Sensors in technology and nature’. the major types of EAPs and their sensing mechanisms.
    [Show full text]
  • Dielectric Studies of Liquid Crystal Nanocomposites and Nanomaterial Systems
    ABSTRACT Title of Thesis: DIELECTRIC STUDIES OF LIQUID CRYSTAL NANOCOMPOSITES AND NANOMATERIAL SYSTEMS. Ravindra Kempaiah, Master of Science, 2016 Thesis Directed By: Assistant Professor, Dr. Zhihong Nie, and Department of Chemistry and Biochemistry Liquid crystals (LCs) have revolutionized the display and communication technologies. Doping of LCs with inorganic nanoparticles such as carbon nanotubes, gold nanoparticles and ferroelectric nanoparticles have garnered the interest of research community as they aid in improving the electro-optic performance. In this thesis, we examine a hybrid nanocomposite comprising of 5CB liquid crystal and block copolymer functionalized barium titanate ferroelectric nanoparticles. This hybrid system exhibits a giant soft-memory effect. Here, spontaneous polarization of ferroelectric nanoparticles couples synergistically with the radially aligned BCP chains to create nanoscopic domains that can be rotated electromechanically and locked in space even after the removal of the applied electric field. We also present the latest results from the dielectric and spectroscopic study of field assisted alignment of gold nanorods. DIELECTRIC STUDIES OF LIQUID CRYSTAL NANOCOMPOSITES AND NANOMATERIAL SYSTEMS. By Ravindra Kempaiah Thesis submitted to the Faculty of the Graduate School of the University of Maryland, College Park, in partial fulfillment of the requirements for the degree of Master of Science 2016 Advisory Committee Assistant Professor Dr. Zhihong Nie, Chair Assistant Professor Dr. Efrain Rodriguez Professor Dr. Jeffery Davis © Copyright by Ravindra Kempaiah 2016 Acknowledgements I am honored by the fact that I have been a member and research student at the University of Maryland and I have immensely benefitted by the research expertise that abounds the reputed labs of this university.
    [Show full text]
  • Non-Equlibrium Structure Affects Ferroelectric Behavior of Confined Polymers
    Non-equlibrium structure affects ferroelectric behavior of confined polymers Daniel Martinez-Tong,1 Alejandro Sanz,2 Jaime Martín,3 TiberioA Ezquerra4 and Aurora Nogales4 1 Université Libre de Bruxelles, Boulevard du Triomphe, Bruxelles 1050, Belgium 2 DNRF Centre “Glass and Time”, IMFUFA, Department of Sciences, Roskilde University, Postbox 260, DK-4000 Roskilde, Denmark 3 Department of Materials and Centre of Plastic Electronics, Imperial College London, London SW7 2AZ, UK 4 Instituto de Estructura de la Materia IEM-CSIC, C/ Serrano 121, Madrid 28006, Spain Abstract The effect of interfaces and confinement in polymer ferroelectric structured is discussed. Results on confinement under different geometries are presented and the comparison of all of them allows to evidence that the presence of an interface in particular cases stabilizes a ferroelectric phase that is not spontaneously formed under normal bulk processing conditions Introduction Polymers are hierarchical systems, with structure in different length scales. Most macroscopic properties of polymers have their origin in physical phenomena associated with length scales of the order of nanometers. Hence, confining poly- mers to the nanoscale may end up in a material with different physical properties. This fact is remarkably important nowadays with the development of polymer ap- plications in devices with smaller and smaller sizes. From the fundamental view- point, for several decades experiments have been designed to evaluate the role of limitation of space in several physical processes, like the glass transition of poly- mers(Alcoutlabi and McKenna, 2005), changes in the dynamics, either local or segmental (Priestley et al., 2015), among others. However, in those designed ex- periments, besides the pure finite size effects, another issue has to be inevitably considered, and that is the presence of interphases, that become extremely im- portant in confinement experiments, when the characteristic size is in the length scale of the interaction of the system with a substrate.
    [Show full text]
  • Ferroelectric Polymers for Organic Electronic Applications Nicoletta Spampinato
    Ferroelectric polymers for organic electronic applications Nicoletta Spampinato To cite this version: Nicoletta Spampinato. Ferroelectric polymers for organic electronic applications. Polymers. Univer- sité de Bordeaux, 2018. English. NNT : 2018BORD0392. tel-02115772 HAL Id: tel-02115772 https://tel.archives-ouvertes.fr/tel-02115772 Submitted on 30 Apr 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. THÈSE PRÉSENTÉE POUR OBTENIR LE GRADE DE DOCTEUR DE L’UNIVERSITÉ DE BORDEAUX École Doctorale des Sciences Chimiques Spécialité : Polymères Par Nicoletta SPAMPINATO FERROELECTRIC POLYMERS FOR ORGANIC ELECTRONIC APPLICATIONS Sous la direction de : Pr. Georges HADZIIOANNOU Co-directeur : Dr. Mario MAGLIONE Soutenue le 18 Décembre 2018 Membres du jury : M. POULIN Philippe, Directeur de Recherche, CRPP - CNRS ExaminateurPrésident du Jury M. GEOGHEGAN Mark, Professeur, University of Sheffield RapporteurRapporteur Mme NOGALES RUIZ Aurora, Directrice de Recherche, IEM - CSIC RapporteuseRapporteuse M. AMEDURI Bruno, Directeur de Recherche, ICGM - CNRS Examinateur M. PORTALE Giuseppe, Maître de Conférences, University of Groningen Examinateur Mme PAVLOPOULOU Eleni, Maître de Conférences, Bordeaux INP IInviténvité M. MAGLIONE Mario, Directeur de Recherche, ICMCB - CNRS Co-directeur de TThèsehèse M. HADZIIOANNOU Georges, Professeur, Université de Bordeaux DirecteurDirecteur dede ThèseThèse 2 “All the effort in the world won't matter if you're not inspired.” C.
    [Show full text]
  • Large Strain Electroactive Polymers for Use in Artificial Muscle Applications
    MEMS 1082 Department of Mechanical Engineering and Materials Science – Electromechanical Sensors and Actuators Fall 2018 Swanson School of Engineering, University of Pittsburgh Large Strain Electroactive Polymers for use in Artificial Muscle Applications Corey May, Wesley Keck, Ryan Black 12/9/2018 Abstract Electroactive polymers (EAPs) are synthetic materials that undergo strain when a voltage or charge is applied, therefore causing deformation. Because of their potential for large strains, EAPs are perfect candidates for applications in both sensors and actuators. Electroactive polymers can undergo deformation when electrical currents are applied because the semi-crystalline structure is polarized causing the positive and negative poles to orient within the material. The deformation and strain within the EAP materials can be determined using the piezoelectric effect and electrostrictive effect equations. The Gibb’s Free Energy equations can be used to determine several transduction effects with EAP materials. The research into EAPs became popular in the early 1990’s, but their use to date has been limited due to power inefficiencies, lack of force production, inability for precision control, and quick degradation of the materials with use. Advances to improve these issues in the last decade have made great strides toward one day being able to use these in many applications. Electroactive polymers have the potential to repair degraded muscles, work as pumps, and give robotics more lifelike movement with better dexterity. MEMS 1082 Department of Mechanical Engineering and Materials Science – Electromechanical Sensors and Actuators Fall 2018 Swanson School of Engineering, University of Pittsburgh Introduction: Humans have always been fascinated with making art inspired by the biological form.
    [Show full text]
  • Mini‐Review: the Promise of Piezoelectric Polymers
    California State University, San Bernardino CSUSB ScholarWorks Physics Faculty Publications Physics 7-2018 Mini‐review: The Promise of Piezoelectric Polymers Timothy D. Usher California State University - San Bernardino, [email protected] Kimberley R. Cousins California State University - San Bernardino, [email protected] Renwu Zhang California State University - San Bernardino, [email protected] Stephen Ducharme University of Nebraska - Lincoln Follow this and additional works at: https://scholarworks.lib.csusb.edu/physics-publications Part of the Physics Commons, and the Polymer Chemistry Commons Recommended Citation Usher, Timothy D.; Cousins, Kimberley R.; Zhang, Renwu; and Ducharme, Stephen, "Mini‐review: The Promise of Piezoelectric Polymers" (2018). Physics Faculty Publications. 1. https://scholarworks.lib.csusb.edu/physics-publications/1 This Article is brought to you for free and open access by the Physics at CSUSB ScholarWorks. It has been accepted for inclusion in Physics Faculty Publications by an authorized administrator of CSUSB ScholarWorks. For more information, please contact [email protected]. Usher Timothy Dwight (Orcid ID: 0000-0002-8894-7279) The promise of piezoelectric polymers Timothy D. Usher,a* Kimberley R. Cousins,b Renwu Zhang,b c Stephen Ducharme, * Correspondence: email: [email protected] a Department of Physics, California State University San Bernardino, USA. b Department of Chemistry and Biochemistry, California State University San Bernardino, USA. c Department of Physics and Astronomy, Nebraska Center for Materials and Nanoscience, University of Nebraska Lincoln, USA. Keywords: Piezoelectricity, ferroelectricity, review, polymer, theory, applications. Abstract Recent advances provide new opportunities in the field of polymer piezoelectric materials. Piezoelectric materials provide unique insights to the fundamental understanding of the solid state.
    [Show full text]
  • Ferroelectric Polymer Thin Films for Organic Electronics
    Hindawi Publishing Corporation Journal of Nanomaterials Volume 2015, Article ID 812538, 14 pages http://dx.doi.org/10.1155/2015/812538 Review Article Ferroelectric Polymer Thin Films for Organic Electronics Manfang Mai,1,2 Shanming Ke,1 Peng Lin,1 and Xierong Zeng1,2 1 College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China 2Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China Correspondence should be addressed to Shanming Ke; [email protected] and Xierong Zeng; [email protected] Received 2 January 2015; Accepted 23 March 2015 Academic Editor: Edward A. Payzant Copyright © 2015 Manfang Mai et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The considerable investigations of ferroelectric polymer thin films have explored new functional devices for flexible electronics industry. Polyvinylidene fluoride (PVDF) and its copolymer with trifluoroethylene (TrFE) are the most commonly used polymer ferroelectric due to their well-defined ferroelectric properties and ease of fabrication into thin films. In this study, we review the recent advances of thin ferroelectric polymer films for organic electronic applications. Initially the properties of ferroelectric polymer and fabrication methods of thin films are briefly described. Then the theoretical polarization switching models for ferroelectric polymer films are summarized and the switching mechanisms are discussed. Lastly the emerging ferroelectric devices based on P(VDF-TrFE) films are addressed. Conclusions are drawn regarding future work on materials and devices.
    [Show full text]
  • Ferroelectric Polymer for Bio-Sonar Replica
    4 Ferroelectric Polymer for Bio-Sonar Replica Antonino S. Fiorillo and Salvatore A. Pullano School of Biomedical Engineering, University of Magna Græcia, Italy 1. Introduction The sensorial knowledge paradigm has captured the interest of many eminent scholars in past centuries (the philosophical trend of “Sensism” was developed around the “Gnoseologic Paradigm”, which has found its highest expression in Étienne Bonnot de Condillac, 1930) as well as in the modern era, particularly in the attempt to interface the external environment to humans through artificial systems. Of the five human senses, which have been investigated by scientists involved in artificial perception studies, vision, touch and hearing have received the most attention, each one for different reasons. When referring to hearing as the sense which perceives sound (the mechanical perturbation induced in a medium by a travelling wave at suitable frequency), a distinction should be made. Indeed, sound between 100 Hz and 18 kHz refers mainly to the range of human perception, while infrasound (up to 20 or 30 Hz) and low frequency ultrasound (from 20 to 120 kHz) refer to animal (mammalian) perception. Low frequency ultrasounds have been amply investigated in the last century and the resulting applications have been made in both military and civil fields. In any case, it appears relevant and necessary to improve the performance of the ultrasonic system (more properly named sonar) for use in a variety of industrial, robotic, and medical applications where ranging plays a basilar role. Nevertheless, other important information can be extrapolated through proper use of the ultrasonic signal as is evident from the study of the biology and mammalian behaviour (Altringham, 1996).
    [Show full text]