"Invisibility Caps" akadali osawoneka

Zaposachedwa kwambiri za "zovala zosawoneka" ndizobadwa ku yunivesite ya Rochester (1), yomwe imagwiritsa ntchito njira yoyenera ya kuwala. Komabe, okayikira amachitcha mtundu wina wa chinyengo kapena zotsatira zapadera, momwe ma lens anzeru amapeputsa kuwala ndikunyenga masomphenya a wowonera.

Pali masamu ena otsogola kwambiri kuseri kwa zonsezi—asayansi akuyenera kuzigwiritsa ntchito kuti apeze momwe angakhazikitsire magalasi awiriwa kuti kuwalako kuwonekere m'njira yoti athe kubisa chinthucho kumbuyo kwawo. Yankho ili silimagwira ntchito poyang'ana mwachindunji pa magalasi - ngodya ya madigiri 15 kapena ina ndiyokwanira.

1. "Invisibility Cap" yochokera ku yunivesite ya Rochester.

Itha kugwiritsidwa ntchito m'magalimoto kuti ichotse madontho akhungu pagalasi kapena m'zipinda zopangira opaleshoni, zomwe zimapangitsa kuti madokotala azitha kuwona kudzera m'manja mwawo. Ichi ndi china mu mndandanda wautali wa mavumbulutso okhudza ukadaulo wosawonekazomwe zabwera kwa ife m'zaka zaposachedwa.

Mu 2012, tidamva kale za "Cap of Invisibility" kuchokera ku American Duke University. Chokhacho chomwe chidawerengedwa kwambiri panthawiyo chinali cha kusawoneka kwa silinda yaying'ono mu kachidutswa kakang'ono ka mawonekedwe a microwave. Chaka m'mbuyomo, akuluakulu a Duke adanenanso zaukadaulo wa sonar stealth womwe ungawoneke ngati wosangalatsa m'magulu ena.

Mwatsoka, zinali kusaoneka kokha kuchokera kumalo enaake komanso pamtunda wopapatiza, zomwe zinapangitsa kuti teknoloji ikhale yosagwiritsidwa ntchito pang'ono. Mu 2013, mainjiniya osatopa ku Duke adapanga chida chosindikizira cha 3D chomwe chidabisala chinthu chomwe chidayikidwa mkati ndi mabowo ang'onoang'ono (2). Komabe, kachiwiri, izi zidachitika pamlingo wocheperako wa mafunde komanso kuchokera pamalingaliro ena.

Pazithunzi zomwe zidasindikizidwa pa intaneti, kape ya kampani yaku Canada Hyperstealth imawoneka yosangalatsa, yomwe mu 2012 idalengezedwa pansi pa dzina lochititsa chidwi la Quantum Stealth (3). Tsoka ilo, ma prototypes ogwira ntchito sanawonetsedwe, komanso sanafotokozedwe momwe amagwirira ntchito. Kampaniyo imatchula zovuta zachitetezo ngati chifukwa chake ndipo ikunena mosabisa kuti ikukonzekera mitundu yachinsinsi yazankhondo.

Monitor wakutsogolo, kamera yakumbuyo

Yoyamba yamakonokusawoneka kapu» Adayambitsidwa zaka khumi zapitazo ndi injiniya waku Japan Prof. Susumu Tachi wochokera ku yunivesite ya Tokyo. Anagwiritsa ntchito kamera yomwe ili kumbuyo kwa bambo wina yemwe anavala jasi lomwe linali lounikiranso. Chithunzi chochokera ku kamera yakumbuyo chidawonetsedwa pamenepo. Munthu wovalayo anali "wosaoneka". Chinyengo chofananachi chimagwiritsidwa ntchito ndi chida chobisala magalimoto cha Adaptiv chomwe chinayambitsidwa zaka khumi zapitazi ndi BAE Systems (4).

Imawonetsa chithunzi cha infrared "kumbuyo" pa zida za tanki. Makina oterowo samawoneka pazida zowonera. Lingaliro la masking zinthu lidapangidwa mu 2006. John Pendry wa ku Imperial College London, David Schurig ndi David Smith wa ku yunivesite ya Duke adafalitsa chiphunzitso cha "transformation optics" mu Science ndikuwonetsa momwe zimagwirira ntchito pa ma microwaves (mafunde aatali kuposa kuwala kowoneka).

2. "Chipewa chosawoneka" chosindikizidwa mu miyeso itatu.

Mothandizidwa ndi ma metamatadium oyenera, mafunde a electromagnetic amatha kupindika m'njira yoti alambalale chinthu chozungulira ndikubwerera kunjira yake. Chizindikiro chodziwika bwino ndi mawonekedwe a sing'anga ndi refractive index, yomwe imatsimikizira kuti ndi kangati pang'onopang'ono kusiyana ndi vacuum, kuwala kumayenda mu sing'anga iyi. Timawerengera ngati muzu wa chinthu chamagetsi ndi maginito permeability.

wachibale magetsi permeability; imatsimikizira kuti mphamvu yolumikizirana yamagetsi mu chinthu choperekedwa ndi yocheperako bwanji kuposa mphamvu yolumikizirana mu vacuum. Choncho, ndi muyeso wa momwe mphamvu zamagetsi zomwe zili mkati mwa chinthu zimayankhira kumunda wamagetsi wakunja. Zinthu zambiri zimakhala ndi chilolezo chabwino, zomwe zikutanthauza kuti munda wosinthidwa ndi chinthucho udakali ndi tanthauzo lofanana ndi lakunja.

Kuthekera kwa maginito m kumatanthawuza momwe mphamvu ya maginito imasinthira mumlengalenga wodzazidwa ndi zinthu zomwe zaperekedwa, poyerekeza ndi mphamvu ya maginito yomwe ingakhale mu vacuum yokhala ndi gwero lakunja lomwelo. Pazinthu zonse zomwe zimachitika mwachilengedwe, mphamvu ya maginito yolumikizana ndi yabwino. Kwa zowulutsa zowonekera monga galasi kapena madzi, zonse zitatu ndizabwino.

Ndiye kuwala, kudutsa mu vacuum kapena mpweya (zigawo za mpweya zimangosiyana pang'ono ndi vacuum) kulowa mkati, zimasinthidwa molingana ndi lamulo la refraction ndipo chiŵerengero cha sine wa ngodya ya zochitika ndi sine ya ngodya ya refraction ndi zofanana ndi refractive index ya sing'anga iyi. Mtengo wake ndi wocheperapo kuposa ziro; ndipo m amatanthauza kuti ma electron mkati mwa sing'anga amasuntha mosiyana ndi mphamvu yopangidwa ndi magetsi kapena maginito.

Izi ndizomwe zimachitika muzitsulo, momwe mpweya wa electron waulere umakhala ndi ma oscillation ake. Ngati ma frequency a electromagnetic wave sakupitilira kuchuluka kwa ma oscillation achilengedwe a ma elekitironi, ndiye kuti ma oscillation awa amawonetsa gawo lamagetsi la mafundewa mogwira mtima kotero kuti sangalole kuti lilowe mkati mwachitsulo komanso kupanga gawo lolunjika mosiyana. kumunda wakunja.

Zotsatira zake, kuloledwa kwa zinthu zotere kumakhala koipa. Polephera kulowa mkati mwachitsulo, ma radiation a electromagnetic amawoneka kuchokera pamwamba pazitsulo, ndipo chitsulocho chimapeza kuwala kwapadera. Bwanji ngati mitundu yonse iwiri yololeza inali yolakwika? Funso limeneli linafunsidwa mu 1967 ndi katswiri wa sayansi ya zakuthambo wa ku Russia Viktor Veselago. Zikuoneka kuti refractive index ya sing'anga yotereyi ndi yoipa ndipo kuwala kumasinthidwa mosiyana kwambiri kusiyana ndi lamulo lachizolowezi la refraction.

5. Kusokoneza koyipa pamwamba pa metamaterial - kuwonera

Kenako mphamvu ya mafunde a electromagnetic imasamutsidwa kutsogolo, koma maxima a electromagnetic wave amasunthira mbali ina ndi mawonekedwe a mphamvuyo ndi mphamvu yosinthidwa. Zinthu zoterezi sizipezeka m'chilengedwe (palibe zinthu zomwe zili ndi maginito osakwanira). Pokhapokha m'mabuku a 2006 omwe tatchulidwa pamwambapa komanso m'mabuku ena ambiri omwe adapangidwa zaka zotsatila, zinali zotheka kufotokoza ndipo, motero, kumanga nyumba zopangira ndi index yotsutsa (5).

Iwo amatchedwa metamatadium. Mawu achi Greek akuti "meta" amatanthauza "pambuyo", ndiye kuti, izi ndizinthu zopangidwa kuchokera kuzinthu zachilengedwe. Ma Metamatadium amapeza zinthu zomwe amafunikira pomanga tinthu tating'onoting'ono tamagetsi totengera mphamvu ya maginito kapena magetsi. Zitsulo zambiri zimakhala ndi mphamvu yamagetsi yolakwika, kotero ndizokwanira kusiya malo omwe amapereka maginito olakwika.

M'malo mwachitsulo chofanana, mawaya achitsulo opyapyala opangidwa ngati mawonekedwe a gridi ya cubic amamangiriridwa ku mbale ya insulating material. Posintha makulidwe a mawaya ndi mtunda wapakati pawo, ndizotheka kusintha ma frequency omwe kapangidwe kake kamakhala ndi vuto lamagetsi. Kuti mupeze kuperewera kwa maginito munjira yosavuta kwambiri, kapangidwe kake kamakhala ndi mphete ziwiri zosweka zopangidwa ndi kondakitala wabwino (mwachitsanzo, golide, siliva kapena mkuwa) ndikulekanitsidwa ndi wosanjikiza wazinthu zina.

Dongosolo loterolo limatchedwa resonator yogawanika - yofupikitsidwa ngati SRR, kuchokera ku Chingerezi. Mpweya wogawira mphete (6). Chifukwa cha mipata ya mphete ndi mtunda pakati pawo, imakhala ndi mphamvu inayake, ngati capacitor, ndipo popeza mphetezo zimapangidwa ndi zinthu zochititsa chidwi, zimakhalanso ndi inductance, i.e. luso kupanga mafunde.

Kusintha kwa maginito akunja kuchokera ku mafunde a electromagnetic kumapangitsa kuti madzi aziyenda mu mphete, ndipo izi zimapanga mphamvu ya maginito. Zikuoneka kuti ndi mapangidwe oyenera, mphamvu ya maginito yopangidwa ndi dongosolo imayendetsedwa mosiyana ndi kunja. Izi zimapangitsa kuti zinthu zomwe zili ndi zinthu zotere zikhale ndi mphamvu ya maginito. Pokhazikitsa magawo a metamaterial system, munthu atha kupeza kuyankha koyipa kwa maginito mumitundu ingapo yamafunde.

meta - nyumba

Maloto a okonzawo ndi kupanga dongosolo limene mafunde amayenda mozungulira chinthucho (7). Mu 2008, asayansi ku yunivesite ya California, Berkeley, kwa nthawi yoyamba m'mbiri, adapanga zida zamitundu itatu zomwe zimakhala ndi index yoyipa ya refractive ya kuwala kowoneka ndi pafupi ndi infrared, kupindika molunjika kosiyana ndi momwe chilengedwe chimakhalira. Adapanga chitsulo chatsopano pophatikiza siliva ndi magnesium fluoride.

Kenako imadulidwa kukhala matrix okhala ndi singano zazing'ono. Chodabwitsa cha refraction choyipa chawonedwa pamafunde a 1500 nm (pafupi ndi infrared). Kumayambiriro kwa 2010, Tolga Ergin wa Karlsruhe Institute of Technology ndi anzake ku Imperial College London adapanga. wosaoneka nsalu yotchinga. Ofufuzawa adagwiritsa ntchito zinthu zomwe zilipo pamsika.

Anagwiritsa ntchito makhiristo a photonic omwe amaikidwa pamwamba kuti aphimbe kansalu kakang'ono kakang'ono pa mbale yagolide. Chifukwa chake metamaterial idapangidwa kuchokera ku magalasi apadera. Magalasi omwe ali moyang'anizana ndi hump pa mbale amakhala m'njira yoti, mwa kupotoza mbali ya mafunde a kuwala, amachotsa kufalikira kwa kuwala pa chotupacho. Poyang’ana mbaleyo pogwiritsa ntchito maikulosikopu, pogwiritsa ntchito kuwala kokhala ndi utali wotalikirana ndi kuwala kooneka, asayansiwo anaona mbale yafulati.

Pambuyo pake, ofufuza ochokera ku Yunivesite ya Duke ndi Imperial College London adatha kupeza mawonekedwe olakwika a radiation ya microwave. Kuti izi zitheke, zinthu zamtundu wa metamaterial ziyenera kukhala zochepa kuposa kutalika kwa kuwala. Chifukwa chake ndizovuta zaukadaulo zomwe zimafunikira kupanga tinthu tating'ono ting'onoting'ono tomwe timafanana ndi kutalika kwa kuwala komwe akuyenera kuwunikira.

Kuwala kowoneka (violet mpaka kufiira) kumakhala ndi kutalika kwa ma nanometer 380 mpaka 780 (nanometer ndi gawo limodzi mwa magawo biliyoni a mita). Akatswiri a sayansi ya zakuthambo ochokera ku yunivesite ya Scottish ya St. Andrews anabwera kudzapulumutsa. Iwo ali ndi gawo limodzi la metamaterial yowirira kwambiri. Masamba a New Journal of Physics amafotokoza za metaflex yomwe imatha kupindika kutalika kwa ma nanometer pafupifupi 620 (kuwala kofiira lalanje).

Mu 2012, gulu la ofufuza a ku America ku yunivesite ya Texas ku Austin linadza ndi chinyengo chosiyana kwambiri ndi ma microwaves. Silinda yokhala ndi mainchesi a 18 cm idakutidwa ndi zinthu zoyipa za plasma, zomwe zimalola kusintha zinthuzo. Ngati ili ndi mawonekedwe owoneka bwino a chinthu chobisika, imapanga mtundu wa "negative".

Choncho, mafunde awiriwa amalumikizana ndipo chinthucho chimakhala chosawoneka. Zotsatira zake, zinthuzo zimatha kupindika ma frequency angapo osiyanasiyana a mafundewa kuti aziyenda mozungulira chinthucho, kutembenukira kumbali ina yake, zomwe sizingawonekere kwa wowonera kunja. Malingaliro ongoganizira akuchulukirachulukira.

Pafupifupi miyezi khumi ndi iwiri yapitayo, Advanced Optical Materials inasindikiza nkhani yokhudza kafukufuku wochititsa chidwi wa asayansi ku yunivesite ya Central Florida. Ndani akudziwa ngati alephera kuthana ndi zoletsa zomwe zilipo pa "zipewa zosaoneka» Zomangidwa ndi metamatadium. Malinga ndi zomwe adafalitsa, kutha kwa chinthucho mumtundu wowoneka bwino ndizotheka.

7. Njira zongoyerekeza zopindirira kuwala pa chinthu chosawoneka

Debashis Chanda ndi gulu lake akufotokoza ntchito ya metamaterial yokhala ndi mawonekedwe atatu. Zinali zotheka kuzipeza chifukwa cha zomwe zimatchedwa. kusindikiza kwa nanotransfer (NTP), komwe kumapanga matepi achitsulo-dielectric. Mndandanda wa refractive ukhoza kusinthidwa ndi njira za nanoengineering. Njira yofalitsira kuwala iyenera kuwongoleredwa pamawonekedwe atatu azinthu zakuthupi pogwiritsa ntchito njira ya electromagnetic resonance.

Asayansi ali osamala kwambiri pamalingaliro awo, koma kuchokera ku kufotokozera kwaukadaulo wawo zikuwonekeratu kuti zokutira za zinthu zotere zimatha kupotoza mafunde a electromagnetic kwambiri. Kuphatikiza apo, momwe zinthu zatsopanozi zimapezekera zimalola kupanga madera akuluakulu, zomwe zidapangitsa ena kulota omenyera nkhondo omwe ali ndi zobisika zotere zomwe zingawathandize. kusaoneka wathunthu, kuyambira masana mpaka masana.

Zida zobisala pogwiritsa ntchito ma metamatadium kapena njira zowunikira sizimayambitsa kutha kwenikweni kwa zinthu, koma kusawoneka kwawo kwa zida zodziwikiratu, ndipo posachedwa, mwina, kwa diso. Komabe, pali kale malingaliro okhwima. Jeng Yi Lee ndi Ray-Kuang Lee ochokera ku National Taiwan Tsing Hua University adapereka lingaliro lachidziwitso cha kuchuluka kwa "cap of invisibility" yomwe imatha kuchotsa zinthu osati kungowona, komanso zenizeni zonse.

Izi zigwira ntchito mofanana ndi zomwe takambirana pamwambapa, koma equation ya Schrödinger idzagwiritsidwa ntchito m'malo mwa ma equation a Maxwell. Mfundo ndi kutambasula chinthu chotheka kuti chikhale chofanana ndi zero. Theoretically, izi ndizotheka pa microscale. Komabe, zidzatenga nthawi yayitali kudikirira kuthekera kwaukadaulo wopanga chophimba choterocho. Monga aliyense"kusawoneka kapu“Zomwe tinganene kuti anali kubisa zinazake kuti tisamuone.