The Influence of Nano-Metamaterials on Facade and Appearance of Buildings

Archive of SID

The influence of nano-metamaterials on facade and appearance of buildings

First Author: Tiam Afshin Affiliation: Bachelor student in Islamic Azad University of Najafabad Email: [email protected]

Second Author: Babak Moradian Affiliation: Professor of Islamic Azad University of Najafabad Email: [email protected]

Third Author: Nader Maleki Affiliation: Professor of Amin University of Foladshahr Email: [email protected]

Abstract

The metamaterials are man-made and created by artificial substances , that can not be found in nature. The first implication of nano metamaterials refers to artificial dielectrics and electronic substances. The important trait of their function , is the manipulation of lights such a circular way around the object that can make them invisible . The present research is following the way to answer these questions , Can these materials be used for improving the operation of facades? Do these materials have any function in architecture or not ? or What kind of revolution may be appeared in architecture by these materials? According to physicians researches about metamaterials , has been indicated that ,these substances have an ability to manipulate the lights then disappear themselves . It is axiomatic that , this trait can be used in many fields specially architecture , if they can be controlled and be considered as an increasing thermal capacity and amplification of acoustic feature. By these characteristics, they can have a suitable role in buildings.

Keywords: nano metamaterials – building’s form and facade – invisible elevation

www.SID.ir Archive of SID

Introduction

Nanotechnology, the buzzword today’s material scientist is “metamaterials”. These substances are tiny engineered structures from exciting composite that are used to manipulate light, sound and radiowaves .The history of metamaterials begins with artificial dielectrics in microwave engineering as it developed just after world war II. Yet , there are seminal explorations of artificial materials for manipulating electromagnetic waves at the end of the 19th century (21) . Hence , the history of metamaterials is essentially a history of developing certain types of manufactured materials, which interact at radio frequency , microwave ,and later optical frequencies , and one of the key application for metamaterials lies in their ability to distortion light to be disappeared . (10)

In this context , metamaterials can be defined as unreal substances but with electromagnetic properties that are inaccessible in nature or are difficult to obtain . Perhaps the most representative metamaterial is the so called “left-handed” one with is characterized by a simultaneously negative permittivity and permeability , thus implying a negative index of refraction these hypothetical media were systematically studied by Victor Veselago in 1960s (31) . To access these unusual material parameters , the constituent unit cells need to be resonated ( but still electrically small) which leads to dispersion . consequently , unlike Kock’s artificial dielectrics , metamaterials are usually dispersive in nature (8) . The solution to the problem of realizing such a left-handed or negative- index (NRI) medium was solved three decades later by Shelby ,Smith and Schultz (25) .

The former century has been the age of artificial materials . One materials that stands out in this regard , is the semiconductor . Revolution in the electronics industry in the last century was made possible , by the ability of semiconductor to microscopically manipulate the flow of electrons . Further advancement in the field prompted scientists to suggest that , the new millennium will be the age of photonic in which artificial materials will be synthesized to microscopically manipulate the flow of electromagnetic waves . One of these will be Left Handed (LHM) materials . Such as new man-made materials often referred to as Negative Index Media (NIM) Backward Wave Media (BWM) , negative (DNG) metamaterial .Fig.1 (9) .

Figure 1: Orientation of the electric E , magnetic H , power P , and phase K vector

Then , In which research has attracted tremendous attention in the past few years because of their electromagnetic properties and ability to guide evanescent field , are significantly different from those of Right Handed Materials (RHMs) . They exhibit simultaneous negative values for permittivity , ε , and permeability , µ , in an overlapping frequency region , science the values are derived from the effect of the composite medium system as a whole ; these are defined as effective permittivity ε and permeability µ . Real value are derived to denote the value of negative index of refraction and

www.SID.ir Archive of SID

wave vectors . This means that in practice losses will occur for given medium used to transmit electromagnetic radiation such as microwave or infrared frequencies , or visible light for example real values describe , either the amplitude or the intensity of a transmitted wave relative to an ancient wave ; while ignoring the negligible loss values (27,26) .

Figure 2: Photograph of the left handed material sample Figure 3: Negative vs Positive refraction

The structure that was used consisted of an array of strip wire to synthesize a negative permittivity and split-ring resonators (capacitively loaded loops ) to synthesize negative permeability ,as shown in Fig.2-3 . The use of an array of inductive wires to synthesize artificial dielectrics with plasma-like behavior was previously reported by Walter Rotman (23) ,(although Rotman never explored the ε < 0 region) and independently by John Pendry (19) . In a slab of conventional material , with an ordinary refractive index-a Right Handed Material- the wave front is transmitted away from the source. In a LHM the front travels toward the source. Although the magnitude and the direction of the flow of energy essentially remains the same in both materials , the impedance of these two materials match . The left-handed property causes to disappear objects and etc… (5,39) . Figure 4 , shows how does metamaterials disappear , according to the researches and theories and investigations in this field, this is the best sample of their implication.

Figure 4: This graphic representation shows how tree active source cloak an incoming circular wave, creating a quiet zone for the object to be cloaked. This is just for one frequency . Credit : Fernando Vasquez .University of Utah (National science foundation)

After reviewing their features and structures , it was possible to predict that , these substances can be used in many fields, then it leaded many persons to research .Viktor Veselago the physician from Russia , by presenting an unbelievable article about , the existent material with negative simultaneous µ and ε , could present the new subject from 1967 (33) . After viktor presentation , that had been

www.SID.ir Archive of SID

spent about 30 years until the first material LH , had been found experimentally. Smith and Colleagues in California and San Diego university suggested that , this was not mundane substance rather than ; it was an effective artificial structure of homogenous (28) . James Clerk Maxwell’s question predicting the existence of electromagnetic radiation propagating at the speed of light were made public in 1865 in 1888 Hertz ; had demonstrated the generation of electromagnetic waves , and that their properties were similar to those of light (24) . Before the start of twenty century , many of the concept now familiar in microwave had been developed . The list include the cylindrical parabolic reflector , dielectric lens , microwave absorbers , the cavity radiator , the radiating iris and the pyramidal electromagnetic horn . Round square and rectangular wave guides were used , with experimental development anticipating by several years Rayleigh’s 1896 theoretical solution (13)

In periodic after all researches, magnetic structure has received extensive attention . One of the first attempts to study the spin wave propagation in periodic systems , was made by Elachi (6) . Recently , an active area of research devoted to the study of metamaterial properties of magnetic crystals is born (11,1) . A comprehensive review of artificial dielectrics , including a rigorous mathematical treatment from that era can be found (7) . Moreover , it is worth mentioning some relevant early work on effective media , including that of Bose who in 1898 used man-made twisted fibers (jute) to rotate the polarization of electromagnetic waves , thus emulating naturally occurring chiral media such as sugar (4) . In a related effort , Lindman in 1914 studied artificial chiral media formed by an ensemble of small wire helices (12) . A new similar investigation was performed by taking as a magnetic material antiferromagnetic (22) . Secondly , a study of the effective properties of a one-dimensional (1D) magnetic crystal consisting of a periodically layered cylindrical nanowire was made and effective magnetic quantities were introduced (34,35) . The calculation of magnetic mode spatial profiles at the edge of BZs (wave vectors) and their characterization by means of the effective wavelength and small wave vector could suggest, an experiment similar to the one performed for mapping vortex-state modes in isolated disks of micrometric size (15)or in 2D arrays of saturated magnetic nanoelements.

Acoustic

In the present article ,an attempt has been tried to negotiate about the characterizations of metamaterials and even their important applications in different aspects. First of all acoustic is considered to demonstrate how much it can be influenced. For many decades ,we have been witnessing an increasing demand for supporting undesirable air noise for human comfort as well as mechanical vibrations in solid structures such as buildings, panels, and machinery in general. In fact noise reduction is one of the key issues for enhancing the quality of life. Because of this matter , Some persons could gather and present some information during history in this part.

In 200, Liu et al , proposed unprecedented structure based on a new Physical concept to open the possibility of breaking the mass density law. The system is known as acoustic metamaterial (AM) or locally resonant sonic crystal (LRSC), and gives a possibility to open acoustic band gaps at sonic frequency range using a reduced-size system . This kind of structure initiates a promising way to develop new designs of panels based on AM , to achieve very high sound transmission loss while keeping the desired panel thickness (40) . One kind of AM plate-based which is considered as a promising solution to achieve light weight and no bulky acoustic barriers , is a plate-type AM made of low frequency resonators distributed on one side or both sides of homogenous elastic plate . The system is one of the most studied structures for acoustic and elastic wave prohibition in the low-

www.SID.ir Archive of SID

frequency range (37,16) . The resonators are of cylindrical shape (pillar or stubs) and provide resonant modes at frequencies way below the Bragg scattering mechanism range ; fixed by periodic distribution of the pillars . Due to the resonance of scatterers , the AM plate produces controlled band gaps for Lamb waves and even guiding them precisely through linear defect modes inside the structures (Fig.5) (17,14) .

Figure 5: Acoustic metamaterial structure in airborne sound configuration. (on the left) with spring-mass resonators , (on the right) with cylindrical pillar resonators.

Then , Pennec et al (38) and Wu et al (30) were the first to introduce this kind of structure using metallic pillars on plate to demonstrate the concept of resonant gap opening for plate waves. Wu et al ,also provided the possibility of a wave- guiding low-frequency plate mode by introducing linear defects inside the AM plate (29) .In the following works ,instead of metallic stube , Oudich et al used either simple soft rubber stubs or composite stub made of rubber with lead or tungsten cap , arranged on the surface of a thin aluminum plate ( stubbed plate) .They demonstrated that , they can lower even more the resonant modes to couple with the Lamb ones (Fig .6) (18) .

Figure 6: Sandwich panel system with either (a) foam or (b) honeycomb structure .Bottom: acoustic metamaterial example.

www.SID.ir Archive of SID

Solar energy

The second essential feature about metamaterials is solar energy . this can be caused to use in many aspects of science and technologies . Nam et al .theoretically predicted a conversion efficiency up to10% for solar thermo photo voltaic (STPV) device with tantalum (Ta) photonic crystals as absorber and emitter (36) , while Lenert at al. experimentally demonstrated an efficiency of 3.2% for the STPV system employing carbon nanotube arrays as the solar absorber and 1D photonic crystals as the selective emitter (2) .The experimental conversion efficiency was further increased to 3.74% with 2D Ta photonic crystal as the absorber and emitter (32) , while an STPV device with further optimized Ta photonic crystals as the absorber and emitter whose measured efficiency exceeds 10% was reported(3) .

Besides photonic crystals, selective absorption/emission for the absorber-emitter module can also be obtained with multilayer cavities and nanoparticle based structures . Recently, film-coupled metamaterials with selective radiative properties have been investigated . These metamaterials are usually in metal-dielectric-metal configurations , with different nanostructures on the top including 1D and 2D convex gratings , trapezoid grating , pyramid , disk and crossbar arrays .Through the excitation of plasmonic resonances such as surface plasmon polarization (SPP) and magnetic polarition (MP) , spectrally selective radiative properties can be obtained in these metamaterials . Note that , the radiative properties can easily be modified by tuning the geometric parameters of the film-coupled structure ,making it feasible to adjust the cutoff wavelengths of the absorber and emitter to fit with the applications in different STPV systems .

FIG.7 shows the energy flow in an STPV system : the incident solar radiation is converted into heat by the solar absorber ,with part of the energy dissipated through reflection and thermal re-emission ; then the heated emitter generates thermal radiation toward the TPV cell , which generates electricity. Note that temperature of the absorber and emitter is associated with their radiative properties and the incident solar flux. Neglecting the temperature difference between the absorber and emitter (i.e .,Tabs =Temit) as well as conduction and convection losses , the energy balance at steady state for the absorber-emitter module yield :

Aabc ( qin _ qref _ qre-emit _ qabc ,side ) = A emit ( qE-PV + qenvi )

Where Aabc and A emit are respectively the top surface area of the solar absorber and the bottom surface area of the TPV emitter. qin is the incident solar radiative heat flux , qref is the reflected solar radiative flux from the absorber , and qre-emit is the heat flux through thermal re-emission from the solar absorber surface .

Figure 7: The schematic and energy flow for an STPV system.

www.SID.ir Archive of SID

This work investigationes an STPV system empoying film-coupled metamaterial as the solar absorber and TPV emmiter, whose vonversion efficiency ranges from 8% to 10% with concentration factor varying between 20 and 200. Due to the soectral selectivity of metamaterials ,the conversion efficiency of the STPV system with black absorber and emitter (<2.5%) .

After considerations another research about geometric structure was being examined for its contribution toward absorbtion characteristics. In FIG.8 , the proposed design consisting of three basic layers is given .The bottom plate is a metallic layer (ground planet) , the intermediate layer is a dielectric host material , and the top layer consist of three patches that are responsible for the EM resonances (20) . Perfect metamaterials absorber based on metallic path resonators was proposed and discussed in this paper . The frequency response of the structure provides two near perfect (nearly 100%) absorption peaks . The geometric parameters of the proposed design are characterized and discussed for their effect on absorption behavior of the proposed PMA where , the design understudy displays a high flexibility and ability to maintain a higher dual-band absorption rate.

Figure 8: (a) perspective view of the proposed MTM structure :unit cell with it is geometric parameters ,(b) a full structure of the proposed design ,(c) top view of the proposed design with additional patchs on the top of each other.

Conclusion

The result of all investigations and researches about metamaterials show, they are functional in architecture . As has been demonstrated by figures , these substances can disappear objects by manipulating lights , then can be sound and heat insulations , even they increase thermal capacity. In architecture facades and forms, operate like a cortex for building , which have the responsibility of controlling and adapting building against the environmental situation ,even they work such a slit for visiting out side. Nano metamaterials can provide necessary item, like the view of our in special time of day and also can provide the demand of being tough simultaneously . Moreover , in the view of urban development sometimes buildings prevent of watching sky and destroy the sky line , by using the manipulation of lights , metamarials solved this problem of urban development view. Even these substances can amplify sound and thermal isolations in buildings.

www.SID.ir Archive of SID

References

1- A . De Baas (Ed.) ,Nanostructured Metamaterials ,The European Commission Publications Office ,2010. 2- A . Lenert ,D .M.Bierman ,Y.Nam, W.R .Chan ,I ,Celavonic ,M. Soljacic, E.N.Wang ,A nano photonic solar thermophotovoltaic device, Nat. Nanotechnol .9 (2014) 126-130. 3- A . Lenert ,V.Rinnerbauer ,D. M. Birman ,Y.Nam ,I.Celanovic,M.Soljacic ,E.N.Wang ,2D Photonic crystals for high spectral conversion efficiency in solar thermophotovoltaics , 2014 IEEE 27th International Conference on Micro Electro Mechanical systems (MEMS) ,2014,pp. 576-579. 4- Bose, J. C .,Proc. R.soc.(1898)63 , 146. 5- Caloz , C., Chang ,C ., and Itoh,T., Full wave verification of the fundamental properties of left handed materials in waveguide configuration .J. of Applied Physics ,2001,90(11) ,5483. 6- C. Elachi , Magnetic Wave Propagation in a periodic medium ,IEEE Transmission on Magnetic MAG-11 (1975) 36-39. 7- Collin, R.E ., Field Theory of Guided Wave, Piscataway ,N.J.:IEEE Press (1990)-chapter 12. 8- EM transmission - line metamaterial (essay), Forth paragraph , line 7-10. 9- Engheta ,N .,and Richard ,w,. Ziolkowski , Metamaterials : Physics and Engineering Exploration, Wiley and Sons ,2006, Chap.1 ,ISBN 978-04717610205. 10- Engheta , Nader ; Richard W.Ziolkowshki (June 2006) . Metamaterials : physics and engineering exploration .Wiley & Sons. 11- H. Hertz , Electric Wave. London: Macmillan and Co.Lts ., 1893. (Reprinted by Dover). 12- Lindell, I. V., et al., IEEE Antennas. Progap . Mag .(1992) 34, 24. 13- Lord Rayleigh, “on the passage of electric waves through tubes, or the vibration of dielectric cylinders, “Phil.Mag.,vol.43,pp.125,125-132,February 1897. 14- M.B . Assouar,M . Senesi, M.Oudich , M.Ruzzene ,Z.Hou,Apple. Phys .Lett. 101(2012) 173505. 15- M.Buess , R.Hollinger ,T .Haug ,K .Perzlmaier ,U.Krey ,D. Pescia ,M.R .Scheinfein , D. Weiss , C. H.Back ,Fourier transform imaging of spin vortex eigenmodes ,Physical Review Letters 93(2004) 077207. 16- M. Oudich, B. Djafari-Rouhani ,Y.Pennec ,M.B .Assouar ,B.Bonello ,J.Apple.Phys .116 (2014)184504. 17- M . Oudich , M.B .Assouar , Z. Hou , Appl, Phys.Lett. 97(2010) 193503 . 18- M .Oudich , Y.Li , M.B .Assouar , Z. Hou ,New J, Phys. 12 (2010) 083049 . 19- Pendry, J .B .,et ., al .Phys .Rev. Lett .(1996) 76, 4773. 20- P.G . Balmaz, O.J.F. Martin , Electromagnetic resonances in individual and coupled split-ring resonators ,J .Apple. Phys . 92(2002) 2929-2936. 21- Ramsay ,John (1958). Microwave antenna and waveguide technic before 1900. Proceeding of the IRE (Abstract) 46 (2): 405. 22- R.H. Tarkhanyn , D.G .Niarchos , M. Kafesaki , Influence of external magnetic field on magnon-plasmon polarizations in negative-index antiferromagnetic-semiconductor superlattices ,Journal of Magnetism and Magnetic Material 322 (2010) 603-608 . 23- Rotman ,W ., IRE Transactions Antennas Propag . (1962)10 ,82. 24- S. A .Nikitov , PH .Tailhades , C.S. Tsai. Spin wave in periodic magnetic structure __magnonic crystals , Journal of Magnetism and Magnetic Materials 236(2001) 320-330. 25- Shelby ,R. A ., et al., Science (2001) 292 , 77. 26- Shelby R ., A .,Smith , D. R ., Schultz and nemat , Nasser S .C ., Microwave transmission through a two dimensional isotropic left handed material . Applied Physics Lett , 2001, 78 (40),77-79. 27- Smith, D.R., Padilla,w.j., Nemat Nasser, S.C ., and Schultz, S., Composite Medium with Simultaneously Negative Permeability and Permittivity .Phys . Rev. Lett ., 2000, 84,4184-4187. 28- Smith , D. R., W. J. Padilla ,D. C. Vier ,et al .,”Composite medium with simultaneously negative permeability and permittivity ,” Physical Review Letters, Vol. 84, No.18, 4184_4187, 2000. 29- T.-C. Wu, T.-T .Wu,J.-C. Hsu, Phys .Rev. B 79 (2009) 104306. 30- T. T. Wu, Z. H.Huang , T.-G. Tsai, T.-C. Wu. Appl. Phys. Lett . 93 (2008) 111902. 31- Veselago , V.G .,Soviet Physics Usphekhi (1968) 10, 509. 32-V. Rinnerbauer, A.Lenert ,D.M.Bireman ,Y.X .Yeng ,W.R.Chan, R.D. Guil,J.J. Senkevich, J.D. Joannopoulos, E.N,Wang, M. Soljacic ,Metallic photonic crystal absorber-emitter for efficient spectral control in high-temperature solar thermophotovoltaics ,Adv.Energy mater. 4(2014) . 33- V. Veselago .” The electrodynamics of substance with simultaneously negative values of µ and ε ,” Soviet Physics Uspekhi ,vol. 10,no. 4, pp. 509_514 , Jan _Feb . 1968.

www.SID.ir Archive of SID

34- V.V .Kruglyak ,R.J . Hichken, A .N .Kuchko, V .Yu . Gorobets , Spin wave in a periodically layered magnetic nanowire ,Journal of Applied Physics 98 (2005) 0143040. 35- V.V. Kruglayak , P.S. Keatly, A, Neudert, R.J. Hicken, J.R. Chil-dress ,J.A. Katine ,Imaging collective magnonic modes in a 2D arrays of magnetic nanoelements ,Physical Review Letters 104(2010)027201. 36- Y. Nam ,y.x.Yeng ,A. Lenert ,P. Bermel, I .Celavonic ,M. Soljacic , E.N. Wang ,Solar thermophotovoltaic energy conversion system with two-dimensional tantalum photonic crystal absorber and emitters ,Sol .Energy Matter .Sol. Cells 122 (2014) 287-296. 37- Y. Pennec ,B. Djafari-Rouhani ,H.Larabi ,A .Akjouj ,J.N .Gillet ,J.O. Vasseur ,G.Thabet ,Phys .Rev .B 80(2009) 144302. 38- Y. Pennec ,B. Djafari-Rouhani ,H.Larabi , J.O.Vasser, A,.-C. Hladky-Hennion ,Phys.Rev .B 78(2008) 1041105. 39- Ziolkowski ,R.W .,and Heyman, E., Wave propagation in media having negative permittivity and permeability .Phys .Rev .E ,2001 ,64, 056625. 40- Z .Liu, X. Zhang ,Y .Mao , Y.Y Zhu, Zh ,Yang ,C .T.Chan ,Ping Sheng ,Science 289(2000) 1734.