DOCSLIB.ORG

Mimicking Bio-Mechanical Principles in Photonic Metamaterials for Giant

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Mimicking Bio-Mechanical Principles in Photonic Metamaterials for Giant ARTICLE https://doi.org/10.1038/s42005-020-0352-0 OPEN Mimicking bio-mechanical principles in photonic metamaterials for giant broadband nonlinearity ✉ Taeyong Chang 1, Suwan Jeon 1, Minsung Heo1 & Jonghwa Shin 1 1234567890():,; Microscopic structuring can change the effective properties of a material by several orders of magnitude. An example of this is animal bone, which has an effective elastic modulus that is more than 1,000 times larger than that of the constituent proteins. Here, we propose a broadband-enhancement principle of photonic nonlinearity that has a similar mathematical origin as the bone example. The proposed staggered array metamaterials violate the standard Miller’s rule in nonlinear optics and can enhance the third-order nonlinearity by more than a thousand to a billion times, depending on target operation frequencies. This metamaterial principle also enables manipulation of the individual components of the linear and nonlinear susceptibility tensors. Our biomimetic approach overcomes the fundamental speed-efficiency trade-off in current resonant enhancement schemes, making faster and more efficient all- optical devices possible for 1.55 μm wavelength. The principle is also applicable to ionic diffusion, heat conduction, or other transport problems. ✉ 1 Department of Materials Science and Engineering, KAIST, Daejeon 34141, Republic of Korea. email: [email protected] COMMUNICATIONS PHYSICS | (2020) 3:79 | https://doi.org/10.1038/s42005-020-0352-0 | www.nature.com/commsphys 1 ARTICLE COMMUNICATIONS PHYSICS | https://doi.org/10.1038/s42005-020-0352-0 onlinear photonic processes, such as harmonic genera- mechanical and electromagnetic properties is presented in the Ntion, phase modulation, and multi-photon absorption, discussion section. have diverse applications including laser sources and From the point of view of materials, SAMMs can be considered optical communications1–3, three-dimensional lithography4, bio- homogeneous, crystalline photonic materials because their imaging5, and many others6–10. However, light–matter interac- periods are much smaller than the wavelength—as those of tion is predominantly linear for common transparent photonic natural crystals—and their effective material properties, such as materials, thus necessitating the injection of high-intensity arti- the linear and nonlinear susceptibilities and refractive indices, are ficial light sources along the optimal crystallographic directions11. well defined and remain constant regardless of the thickness of Therefore, numerous studies have been conducted with the aim to the sample22–24. For these metamaterials, their linear (n = 1) and attain photonic nonlinearity enhancement. Most of these studies χ~ðnÞ nonlinear (n > 1) homogenized electric susceptibilities eff can be have focused on the introduction of tailored electromagnetic reso- 13,19,25 – calculated based on the reciprocity theorem using the nances near the operation wavelength to boost light matter inter- χ~ðnÞð Þ 12–19 electric susceptibility tensors, d r , of the constituent materials actions . Both quantum-electrodynamic approaches involving ðωÞ 12,13 fi ð Þ¼ the engineering of intersubband transition energy levels ,and themselves and point-wise eld-enhancement factors, Fαi r classical electrodynamic enhancement methods—mostly utilizing α Á ðωÞð Þ=j ðωÞj ðωÞjj fi – Eloc r Eave (with Eave i), which quanti es how strong the photonic cavities or resonant structures13 19—have been proposed. ðωÞ α-directional components of the local electric fields (E ðrÞ) are However, these resonant-enhancement schemes exhibit an inherent loc fi ðωÞ trade-off relationship between the degree of enhancement and the when the homogenized, macroscopic electric eld (Eave ) is along frequency bandwidth, thereby hindering their practical applications. the i-direction. α and i are the unit vectors in the α- and i- Even for applications that do not require large bandwidths, large directions, respectively (see Methods and Supplementary Note 1 resonance-induced energy losses and a narrow fabrication error for detailed derivation). margin represent substantial obstacles. Moreover, only a few studies Using this approach, one can analytically derive the homo- have investigated the controllability of the tensor form of nonlinear genized nonlinear susceptibility tensor of the proposed structure susceptibilities10,13,18, despite the fact that it may have important for second-harmonic generation (SHG). In this section, we practical consequences. assume for the sake of simplicity, the use of a metal with perfect Here, we achieve both extreme enhancement and tensor form electric conductivity and an insulator with frequency- controllability of the linear and nonlinear susceptibilities of a independent nonlinear coefficients, thus resulting in the Klein- nonlinear staggered array metamaterial (SAMM) over a broad man symmetry condition11,26 formulated according to ðωÞ ðnωÞ bandwidth. The SAMM represents a periodic composite system Fβγ ¼ Fβγ ¼ Fβγ. These restrictions are eliminated in the of nonlinear materials and conductors with a deep subwavelength rigorous analysis of the actual enhancements and numerical period. We analytically and numerically verify that the third- demonstrations presented in the following sections. For the 9 order nonlinear susceptibility can be enhanced by more than 10 proposed structure, the local electric field is mainly oriented in 4 times at terahertz frequencies and by 10 times at optical tele- the z-direction inside the dielectric layers owing to the parallel- communication frequencies. In addition, we show that 18 dif- plate capacitor-like geometry of the metal plates above and below ferent crystal classes with second-order nonlinearity can be the dielectric. Subsequently, the relevant field-enhancement realized based on simple variations of the spatial configuration of factors are only Fzx, Fzy, and Fzz, and other factors are being a given nonlinear material and a conductor. The proposed negligibly small. The z-directional local electric field- broadband-enhancement principle is mathematically analogous enhancement factors under an x-directional macroscopic electric to that of naturally occurring mechanical SAMMs, such as animal fi fi = = eld, Fzx, of a speci c structure (ax 4800 nm, ay 800 nm, bones and bone-like materials (e.g., nacre and sea shell), which = = = – gx,y 0.2ax,y, and hd hm 20 nm) is plotted in Fig. 1e f (see have enhanced elastic modulus by more than three orders of Methods). The actual profiles of F and F are very simple with a 20,21 zx zy magnitude compared to their constituent soft proteins . large and almost spatially uniform value (around 120 in the aforementioned case) throughout the space between the top and bottom metal plates, and with a negligible value elsewhere. These Results fi = maximum eld-enhancement values are approximately |Fzx | Bespoke nonlinear susceptibility tensor of the proposed = 27 0.5ax/hd and |Fzy | 0.5ay/hd . For the nonlinear dielectric, we SAMM. The proposed SAMM structure is composed of alter- assume that the microscopic pole directions are either the +z-or nating metal and nonlinear dielectric layers (Fig. 1a). The metal −z-direction or unpoled, thus resulting in the intrinsic second- layers are composed of insulated metal patches in a planar lattice, ð Þ ð Þ order nonlinear susceptibility of the form χ 2 ðrÞ¼χ 2 pðrÞ with and the nearest metal layers are staggered with half-unit-cell 33 33 r =+ − shifts in both the x- and y-directions (denoted as “A” and “B” p( ) 1, 1, or 0, respectively. As a representative example, we fi fi r = layers in Fig. 1a). The metal and nonlinear dielectric layers (‘I’) consider a speci c spatial pole con guration of p( ) sign r – are stacked in the sequence A–I–B–I–. The lateral unit-cell [Fzy( )]. Figure 1g h show z-directional local second-order dimensions in the x- and y-directions, the lateral gap sizes in the nonlinear enhancement factor under an x-directional macro- fi χð2Þ 2 =jχð2Þj same directions, and the thicknesses of the metal and dielectric scopic electric eld, 33 Fzx 33 , of this example. The nonlinear layers are denoted as ax and ay, gx and gy, and hm and hd, enhancement factor is very large (around 14,000) and spatially respectively. Figure 1b depicts one unit cell of the SAMM. nearly uniform throughout the aforementioned high-field region The proposed microscopic (subwavelength) structure closely between plates. The contracted notation11,26,28 of the effective resembles the mechanical microscopic structure of mineralized nonlinear susceptibility simplifies to collagen fibrils in animal bone and other hard biological materials 0 1 a 2 ay 20,21 fi fi 000001 ð x Þ ð Þ (Fig. 1c) . In a simpli ed model, the brils in the bones are an B 16 hd hd C ð Þ ð Þ B a a a C array of isolated hard mineral plates embedded in a soft protein 2 2 1 ðax Þ2ð y Þðy Þ3 ð y Þ χ~ ¼ χ ; B 00 0 C matrix, and the mineral plates are in a staggered formation as in eff d 33@ 16 hd hd hd hd A Fig. 1a. Figure 1d schematically shows the microscopic deforma- ðay Þ 000h 00 tion of the mechanical SAMM under macroscopic tensile strain. d ð Þ The mathematical parallelism between the enhancement of 1 2 COMMUNICATIONS PHYSICS | (2020) 3:79 | https://doi.org/10.1038/s42005-020-0352-0 | www.nature.com/commsphys COMMUNICATIONS PHYSICS | https://doi.org/10.1038/s42005-020-0352-0 ARTICLE Fig. 1 Staggered-array metamaterial (SAMM) with extremely enhanced electromagnetic nonlinearity. a A schematic of the proposed SAMM structure. The structure is infinitely periodic in all three Cartesian directions. b A single unit cell of the crystal and the positions of representative cross-sections. The cross-sections normal to the x-, y-, and z-axes are denoted as ‘csx’, ‘csy’, and ‘csz’, respectively. c A macroscopic image and a schematic of the microscopic structure of the bone (adapted by permission from Springer Nature Customer Service Centre GmbH: Springer, Int. J. Fract., Gao21). d Microscopic structure of bone fiber with and without macroscopic tensile strain.
Load more

Recommended publications
  • Role of Dielectric Materials in Electrical Engineering B D Bhagat
    ISSN: 2319-5967 ISO 9001:2008 Certified International Journal of Engineering Science and Innovative Technology (IJESIT) Volume 2, Issue 5, September 2013 Role of Dielectric Materials in Electrical Engineering B D Bhagat Abstract- In India commercially industrial consumer consume more quantity of electrical energy which is inductive load has lagging power factor. Drawback is that more current and power required. Capacitor improves the power factor. Commercially manufactured capacitors typically used solid dielectric materials with high permittivity .The most obvious advantages to using such dielectric materials is that it prevents the conducting plates the charges are stored on from coming into direct electrical contact. I. INTRODUCTION Dielectric materials are those which are used in condensers to store electrical energy e.g. for power factor improvement in single phase motors, in tube lights etc. Dielectric materials are essentially insulating materials. The function of an insulating material is to obstruct the flow of electric current while the function of dielectric is to store electrical energy. Thus, insulating materials and dielectric materials differ in their function. A. Electric Field Strength in a Dielectric Thus electric field strength in a dielectric is defined as the potential drop per unit length measured in volts/m. Electric field strength is also called as electric force. If a potential difference of V volts is maintained across the two metal plates say A1 and A2, held l meters apart, then Electric field strength= E= volts/m. B. Electric Flux in Dielectric It is assumed that one line of electric flux comes out from a positive charge of one coulomb and enters a negative charge of one coulombs.
    [Show full text]
  • Chapter 5 Capacitance and Dielectrics
    Chapter 5 Capacitance and Dielectrics 5.1 Introduction...........................................................................................................5-3 5.2 Calculation of Capacitance ...................................................................................5-4 Example 5.1: Parallel-Plate Capacitor ....................................................................5-4 Interactive Simulation 5.1: Parallel-Plate Capacitor ...........................................5-6 Example 5.2: Cylindrical Capacitor........................................................................5-6 Example 5.3: Spherical Capacitor...........................................................................5-8 5.3 Capacitors in Electric Circuits ..............................................................................5-9 5.3.1 Parallel Connection......................................................................................5-10 5.3.2 Series Connection ........................................................................................5-11 Example 5.4: Equivalent Capacitance ..................................................................5-12 5.4 Storing Energy in a Capacitor.............................................................................5-13 5.4.1 Energy Density of the Electric Field............................................................5-14 Interactive Simulation 5.2: Charge Placed between Capacitor Plates..............5-14 Example 5.5: Electric Energy Density of Dry Air................................................5-15
    [Show full text]
  • Super-Resolution Imaging by Dielectric Superlenses: Tio2 Metamaterial Superlens Versus Batio3 Superlens
    hv photonics Article Super-Resolution Imaging by Dielectric Superlenses: TiO2 Metamaterial Superlens versus BaTiO3 Superlens Rakesh Dhama, Bing Yan, Cristiano Palego and Zengbo Wang * School of Computer Science and Electronic Engineering, Bangor University, Bangor LL57 1UT, UK; [email protected] (R.D.); [email protected] (B.Y.); [email protected] (C.P.) * Correspondence: [email protected] Abstract: All-dielectric superlens made from micro and nano particles has emerged as a simple yet effective solution to label-free, super-resolution imaging. High-index BaTiO3 Glass (BTG) mi- crospheres are among the most widely used dielectric superlenses today but could potentially be replaced by a new class of TiO2 metamaterial (meta-TiO2) superlens made of TiO2 nanoparticles. In this work, we designed and fabricated TiO2 metamaterial superlens in full-sphere shape for the first time, which resembles BTG microsphere in terms of the physical shape, size, and effective refractive index. Super-resolution imaging performances were compared using the same sample, lighting, and imaging settings. The results show that TiO2 meta-superlens performs consistently better over BTG superlens in terms of imaging contrast, clarity, field of view, and resolution, which was further supported by theoretical simulation. This opens new possibilities in developing more powerful, robust, and reliable super-resolution lens and imaging systems. Keywords: super-resolution imaging; dielectric superlens; label-free imaging; titanium dioxide Citation: Dhama, R.; Yan, B.; Palego, 1. Introduction C.; Wang, Z. Super-Resolution The optical microscope is the most common imaging tool known for its simple de- Imaging by Dielectric Superlenses: sign, low cost, and great flexibility.
    [Show full text]
  • Measurement of Dielectric Material Properties Application Note
    with examples examples with solutions testing practical to show written properties. dielectric to the s-parameters converting for methods shows Italso analyzer. a network using materials of properties dielectric the measure to methods the describes note The application | | | | Products: Note Application Properties Material of Dielectric Measurement R&S R&S R&S R&S ZNB ZNB ZVT ZVA ZNC ZNC Another application note will be will note application Another <Application Note> Kuek Chee Yaw 04.2012- RAC0607-0019_1_4E Table of Contents Table of Contents 1 Overview ................................................................................. 3 2 Measurement Methods .......................................................... 3 Transmission/Reflection Line method ....................................................... 5 Open ended coaxial probe method ............................................................ 7 Free space method ....................................................................................... 8 Resonant method ......................................................................................... 9 3 Measurement Procedure ..................................................... 11 4 Conversion Methods ............................................................ 11 Nicholson-Ross-Weir (NRW) .....................................................................12 NIST Iterative...............................................................................................13 New non-iterative .......................................................................................14
    [Show full text]
  • Frequency Dependence of the Permittivity
    Frequency dependence of the permittivity February 7, 2016 In materials, the dielectric “constant” and permeability are actually frequency dependent. This does not affect our results for single frequency modes, but when we have a superposition of frequencies it leads to dispersion. We begin with a simple model for this behavior. The variation of the permeability is often quite weak, and we may take µ = µ0. 1 Frequency dependence of the permittivity 1.1 Permittivity produced by a static field The electrostatic treatment of the dielectric constant begins with the electric dipole moment produced by 2 an electron in a static electric field E. The electron experiences a linear restoring force, F = −m!0x, 2 eE = m!0x where !0 characterizes the strength of the atom’s restoring potential. The resulting displacement of charge, eE x = 2 , produces a molecular polarization m!0 pmol = ex eE = 2 m!0 Then, if there are N molecules per unit volume with Z electrons per molecule, the dipole moment per unit volume is P = NZpmol ≡ 0χeE so that NZe2 0χe = 2 m!0 Next, using D = 0E + P E = 0E + 0χeE the relative dielectric constant is = = 1 + χe 0 NZe2 = 1 + 2 m!00 This result changes when there is time dependence to the electric field, with the dielectric constant showing frequency dependence. 1 1.2 Permittivity in the presence of an oscillating electric field Suppose the material is sufficiently diffuse that the applied electric field is about equal to the electric field at each atom, and that the response of the atomic electrons may be modeled as harmonic.
    [Show full text]
  • Low-K Dielectrics
    Low- κ Dielectrics Prof. Krishna Saraswat Department of Electrical Engineering Stanford University Stanford, CA 94305 [email protected] araswat tanford University 1 EE311/ Low-k Dielectrics Performance Metrics • Signaling • Clocking • Delay • Timing uncertainty • Power dissipation (skew and jitter) • Bandwidth • Power dissipation • Self heating • Slew rate • Data reliability (Noise) • Area • Cross talk • ISI: impedance mismatch • Power Distribution • Area • Supply reliability • Reliability • Electromigration • Depend on R, C and L ! • Function and length dictates relative importance araswat tanford University 2 EE311/ Low-k Dielectrics 1 Interplay Between Signaling Metrics M3 CILD H M2 W CIMD AR=H/W M1 RC-Delay * ' RCinttot • AR increase (tradeoffs)=> Power 2 – Better delay and electromigration P =)CinttotV f 'Cinttot – Worse power and cross talk Crosstalk C 1 • Increasing aspect ratio may not help X ' IMD = talk C ( inttot & ILD # Pay attention to different metrics simultaneously $ ( ! • 1+ % IMD " •Design window quite complex AR2 araswat •Capacitance very important tanford University 3 EE311/ Low-k Dielectrics Dielectric Constant • The dielectric constant, κ, is a physical measure of the electric polarizability of a material • Electric polarizability is the tendency of a material to allow an externally applied electric field to induce electric dipoles (separated positive and negative charges) in the material. Polarization P is related to the electric field E and the displacement D by D = εoE + P • P is related to E through χe the
    [Show full text]
  • Chapter 1 ELECTROMAGNETICS of METALS
    Chapter 1 ELECTROMAGNETICS OF METALS While the optical properties of metals are discussed in most textbooks on condensed matter physics, for convenience this chapter summarizes the most important facts and phenomena that form the basis for a study of surface plas- mon polaritons. Starting with a cursory review of Maxwell’s equations, we describe the electromagnetic response both of idealized and real metals over a wide frequency range, and introduce the fundamental excitation of the conduc- tion electron sea in bulk metals: volume plasmons. The chapter closes with a discussion of the electromagnetic energy density in dispersive media. 1.1 Maxwell’s Equations and Electromagnetic Wave Propagation The interaction of metals with electromagnetic fields can be firmly under- stood in a classical framework based on Maxwell’s equations. Even metallic nanostructures down to sizes on the order of a few nanometres can be described without a need to resort to quantum mechanics, since the high density of free carriers results in minute spacings of the electron energy levels compared to thermal excitations of energy kBT at room temperature. The optics of met- als described in this book thus falls within the realms of the classical theory. However, this does not prevent a rich and often unexpected variety of optical phenomena from occurring, due to the strong dependence of the optical prop- erties on frequency. As is well known from everyday experience, for frequencies up to the vis- ible part of the spectrum metals are highly reflective and do not allow elec- tromagnetic waves to propagate through them. Metals are thus traditionally employed as cladding layers for the construction of waveguides and resonators for electromagnetic radiation at microwave and far-infrared frequencies.
    [Show full text]
  • Nano-Optomechanical Nonlinear Dielectric Metamaterials
    Nano-optomechanical Nonlinear Dielectric Metamaterials Artemios Karvounis1, Jun-Yu Ou1, Weiping Wu1, Kevin F. MacDonald1, and Nikolay I. Zheludev1, 2 1 Optoelectronics Research Centre & Centre for Photonic Metamaterials, University of Southampton, Southampton, SO17 1BJ, UK 2 The Photonics Institute & Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore 637371 By harnessing the resonant nature of localized electromagnetic modes in a nanostructured silicon membrane, an all-dielectric metamaterial can act as nonlinear medium at optical telecommunications wavelengths. We show that such metamaterials provide extremely large optomechanical nonlinearities, operating at intensities of only a few μW per unit cell and modulation frequencies as high as 152 MHz, thereby offering a path to fast, compact and energy efficient all-optical metadevices. Non-metallic metamaterial nanostructures currently of radiative losses in resonant plasmonic metamaterials, attract intense attention as they promise to reduce the as non-radiative losses (Joule heating) are unavoidable in losses and costs associated with the use of noble metals the constituent metals. In ‘all-dielectric’ metamaterials in traditional plasmonic architectures.1 It has already non-radiative losses are a-priori limited, so with been shown that oxides and nitrides,2 graphene,3 appropriate design they can present even stronger optical topological insulators,4 and high-index dielectrics5-13 can resonances, and thereby generate stronger optical forces, be used
    [Show full text]
  • B.Sc. Physics (SECOND YEAR)
    B.Sc. Physics (SECOND YEAR) Paper II Electromagnetics UNIT-III Dielectric Materials • Dielectric materials are a type of electrical insulators that can be polarized through an external applied electric filed. • These materials, generally, do not contain any free charge carriers for conduction. • In such dielectric materials, positive and negative charge entities are bounded together. • The behaviour of dielectric materials can be modified by an external electric field through reorienting the charges within the atom or molecules. • Generally, these materials do not have any net dipole moment in absence of external electric field. • As a consequence of applied electric field, positive charge of dielectric is pushed in direction of the field while negative the opposite way. The overall effect is a displacement of entire positive charge in the dielectric relative to the negative charge, formed induced electric dipoles. • Dielectric materials are classifiedDS into two categories, named as polar molecules and non-polar molecules. Electric Dipole and Electric Dipole Moment 1 An electric dipole is an entity in which equal positive (+q) and negative (-q) charges are separated by a small distance (dl) and the resultant electric dipole moment ( ) due to it is given by, ⃗ = The electric dipole⃗ moment ���⃗ is a vector quantity and it is directed from negative charge to positive charge as shown in adjacent figure. Non-polar and Polar Molecules If the centre of gravity of the positive and negative charges in a molecule are separated by a short distance, such molecules are known as Polar Molecules. It behaves as an electric dipole with direction of dipole moment from negative charge to positive charge.
    [Show full text]
  • All-Dielectric Metamaterials: Irrelevance of Negative Refraction to Overlapped Mie Resonances
    Michigan Technological University Digital Commons @ Michigan Tech Michigan Tech Publications 10-20-2017 All-dielectric metamaterials: irrelevance of negative refraction to overlapped Mie resonances Navid Gandji Michigan Technological University George Semouchkin Michigan Technological University, [email protected] Elena Semouchkina Michigan Technological University, [email protected] Follow this and additional works at: https://digitalcommons.mtu.edu/michigantech-p Part of the Civil and Environmental Engineering Commons, and the Computer Sciences Commons Recommended Citation Gandji, N., Semouchkin, G., & Semouchkina, E. (2017). All-dielectric metamaterials: irrelevance of negative refraction to overlapped Mie resonances. Journal of Physics D: Applied Physics, 50(45). http://dx.doi.org/ 10.1088/1361-6463/aa89d3 Retrieved from: https://digitalcommons.mtu.edu/michigantech-p/655 Follow this and additional works at: https://digitalcommons.mtu.edu/michigantech-p Part of the Civil and Environmental Engineering Commons, and the Computer Sciences Commons Journal of Physics D: Applied Physics PAPER All-dielectric metamaterials: irrelevance of negative refraction to overlapped Mie resonances To cite this article: N P Gandji et al 2017 J. Phys. D: Appl. Phys. 50 455104 Manuscript version: Accepted Manuscript Accepted Manuscript is “the version of the article accepted for publication including all changes made as a result of the peer review process, and which may also include the addition to the article by IOP Publishing of a header, an article ID, a cover sheet and/or an ‘Accepted Manuscript’ watermark, but excluding any other editing, typesetting or other changes made by IOP Publishing and/or its licensors” This Accepted Manuscript is © © 2017 IOP Publishing Ltd. During the embargo period (the 12 month period from the publication of the Version of Record of this article), the Accepted Manuscript is fully protected by copyright and cannot be reused or reposted elsewhere.
    [Show full text]
  • Electrostatic Forces and Stored Energy for Deformable Dielectric Materials
    Electrostatic Forces and Stored Energy for Deformable Dielectric Materials An isothermal energy balance is formulated for a system consisting of deformable dielec- tric bodies, electrodes, and the surrounding space. The formulation in this paper is Robert M. McMeeking obtained in the electrostatic limit but with the possibility of arbitrarily large deformations Fellow ASME of polarizable material. The energy balance recognizes that charges may be driven onto Department of Mechanical and Environmental or off of the electrodes, a process accompanied by external electrical work; mechanical Engineering and Materials Department, loads may be applied to the bodies, thereby doing work through displacements; energy is University of California, stored in the material by such features as elasticity of the lattice, piezoelectricity, and Santa Barbara, CA 93106 dielectric and electrostatic interactions; and nonlinear reversible material behavior such e-mail: [email protected] as electrostriction may occur. Thus the external work is balanced by (1) internal energy consisting of stress doing work on strain increments, (2) the energy associated with Chad M. Landis permeating free space with an electric field, and (3) by the electric field doing work on Mem. ASME increments of electric displacement or, equivalently, polarization. For a conservative Department of Mechanical Engineering and system, the internal work is stored reversibly in the body and in the underlying and Materials Science, surrounding space. The resulting work statement for a conservative system is considered Rice University, in the special cases of isotropic deformable dielectrics and piezoelectric materials. We Houston, TX 77251 identify the electrostatic stress, which provides measurable information quantifying the e-mail: [email protected] electrostatic effects within the system, and find that it is intimately tied to the constitutive formulation for the material and the associated stored energy and cannot be independent of them.
    [Show full text]
  • Dielectric Science and Technology
    only free electrons, as in metals, can respond to the electric field. That is why metals are such good optical reflectors! For nonequilibrium phenomena, the combination of Maxwell’s equations and the continuity equations show that the conductivity tensor, σ, is related to the dielectric tensor, ε. Even the various thermal and mechanical properties, such as thermal expansion, bulk modulus, thermal conductivity, specific heat, and refractive index, are related to the complex dielectric constant, because they depend on the arrangement and Dielectric Science mutual interaction of charges in the material. Thus, the study of dielectrics is fundamental in nature and offers a unified understanding of many other and Technology disciplines in materials science. by Bill Brown, Dennis Hess, Vimal Desai, and M. Jamal Deen �������� ������������� The Dielectric Science and Technology (DS&T) Division � celebrated its 60th anniversary in 2005 as a division within The ����������������������� Electrochemical Society (ECS). As with other Divisions, DS&T provides a forum for its members to exchange scientifi c ideas � through sponsored and co-sponsored symposia, publication � of papers, and other activities. The objective of the Division as was stated in 1952 by its chair, T. D. Callinan, is “to promote ������������������ the attainment and dissemination of knowledge of dielectrics, including the electrical, mechanical, and chemical properties � � � � of nonconductors of electricity.” Thus, a multidisciplinary approach is necessary to develop a fundamental
    [Show full text]