{"id":"https://openalex.org/W4226532731","doi":"https://doi.org/10.1109/access.2022.3157634","title":"Overview of Planar Antenna Loading Metamaterials for Gain Performance Enhancement: The Two Decades of Progress","display_name":"Overview of Planar Antenna Loading Metamaterials for Gain Performance Enhancement: The Two Decades of Progress","publication_year":2022,"publication_date":"2022-01-01","ids":{"openalex":"https://openalex.org/W4226532731","doi":"https://doi.org/10.1109/access.2022.3157634"},"language":"en","primary_location":{"id":"doi:10.1109/access.2022.3157634","is_oa":true,"landing_page_url":"https://doi.org/10.1109/access.2022.3157634","pdf_url":"https://ieeexplore.ieee.org/ielx7/6287639/9668973/09729873.pdf","source":{"id":"https://openalex.org/S2485537415","display_name":"IEEE Access","issn_l":"2169-3536","issn":["2169-3536"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310319808","host_organization_name":"Institute of Electrical and Electronics Engineers","host_organization_lineage":["https://openalex.org/P4310319808"],"host_organization_lineage_names":["Institute of Electrical and Electronics Engineers"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"IEEE Access","raw_type":"journal-article"},"type":"article","indexed_in":["crossref","doaj"],"open_access":{"is_oa":true,"oa_status":"gold","oa_url":"https://ieeexplore.ieee.org/ielx7/6287639/9668973/09729873.pdf","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5007255773","display_name":"Bashar A. F. Esmail","orcid":"https://orcid.org/0000-0002-3627-2177"},"institutions":[{"id":"https://openalex.org/I123185442","display_name":"Reykjav\u00edk University","ror":"https://ror.org/05d2kyx68","country_code":"IS","type":"education","lineage":["https://openalex.org/I123185442"]}],"countries":["IS"],"is_corresponding":false,"raw_author_name":"Bashar A. F. Esmail","raw_affiliation_strings":["Department of Engineering, Reykjavik University, Reykjavik, Iceland"],"raw_orcid":"https://orcid.org/0000-0002-3627-2177","affiliations":[{"raw_affiliation_string":"Department of Engineering, Reykjavik University, Reykjavik, Iceland","institution_ids":["https://openalex.org/I123185442"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5040400589","display_name":"S\u0142awomir Kozie\u0142","orcid":"https://orcid.org/0000-0002-9063-2647"},"institutions":[{"id":"https://openalex.org/I123185442","display_name":"Reykjav\u00edk University","ror":"https://ror.org/05d2kyx68","country_code":"IS","type":"education","lineage":["https://openalex.org/I123185442"]}],"countries":["IS"],"is_corresponding":false,"raw_author_name":"Slawomir Koziel","raw_affiliation_strings":["Department of Engineering, Reykjavik University, Reykjavik, Iceland"],"raw_orcid":"https://orcid.org/0000-0002-9063-2647","affiliations":[{"raw_affiliation_string":"Department of Engineering, Reykjavik University, Reykjavik, Iceland","institution_ids":["https://openalex.org/I123185442"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5001202442","display_name":"Stanis\u0142aw Szczepa\u0144ski","orcid":"https://orcid.org/0000-0002-3110-7893"},"institutions":[{"id":"https://openalex.org/I169333911","display_name":"Gda\u0144sk University of Technology","ror":"https://ror.org/006x4sc24","country_code":"PL","type":"education","lineage":["https://openalex.org/I169333911"]}],"countries":["PL"],"is_corresponding":false,"raw_author_name":"Stanislaw Szczepanski","raw_affiliation_strings":["Faculty of Electronics, Telecommunications and Informatics, Gda\u00f1sk University of Technology, Gda\u00f1sk, Poland"],"raw_orcid":"https://orcid.org/0000-0002-3110-7893","affiliations":[{"raw_affiliation_string":"Faculty of Electronics, Telecommunications and Informatics, Gda\u00f1sk University of Technology, Gda\u00f1sk, Poland","institution_ids":["https://openalex.org/I169333911"]}]}],"institutions":[],"countries_distinct_count":2,"institutions_distinct_count":3,"corresponding_author_ids":[],"corresponding_institution_ids":[],"apc_list":{"value":1850,"currency":"USD","value_usd":1850},"apc_paid":{"value":1850,"currency":"USD","value_usd":1850},"fwci":3.2289,"has_fulltext":true,"cited_by_count":59,"citation_normalized_percentile":{"value":0.93501277,"is_in_top_1_percent":false,"is_in_top_10_percent":true},"cited_by_percentile_year":{"min":97,"max":100},"biblio":{"volume":"10","issue":null,"first_page":"27381","last_page":"27403"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T10245","display_name":"Metamaterials and Metasurfaces Applications","score":0.9998999834060669,"subfield":{"id":"https://openalex.org/subfields/2504","display_name":"Electronic, Optical and Magnetic Materials"},"field":{"id":"https://openalex.org/fields/25","display_name":"Materials Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T10245","display_name":"Metamaterials and Metasurfaces Applications","score":0.9998999834060669,"subfield":{"id":"https://openalex.org/subfields/2504","display_name":"Electronic, Optical and Magnetic Materials"},"field":{"id":"https://openalex.org/fields/25","display_name":"Materials Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T11383","display_name":"Advanced Antenna and Metasurface Technologies","score":0.9998999834060669,"subfield":{"id":"https://openalex.org/subfields/2202","display_name":"Aerospace Engineering"},"field":{"id":"https://openalex.org/fields/22","display_name":"Engineering"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10069","display_name":"Antenna Design and Analysis","score":0.9997000098228455,"subfield":{"id":"https://openalex.org/subfields/2202","display_name":"Aerospace Engineering"},"field":{"id":"https://openalex.org/fields/22","display_name":"Engineering"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/metamaterial","display_name":"Metamaterial","score":0.7065852284431458},{"id":"https://openalex.org/keywords/directivity","display_name":"Directivity","score":0.5281151533126831},{"id":"https://openalex.org/keywords/metamaterial-antenna","display_name":"Metamaterial antenna","score":0.4950358271598816},{"id":"https://openalex.org/keywords/permittivity","display_name":"Permittivity","score":0.4624597728252411},{"id":"https://openalex.org/keywords/directional-antenna","display_name":"Directional antenna","score":0.4147842526435852},{"id":"https://openalex.org/keywords/electronic-engineering","display_name":"Electronic engineering","score":0.3867322504520416},{"id":"https://openalex.org/keywords/materials-science","display_name":"Materials science","score":0.3735559582710266},{"id":"https://openalex.org/keywords/computer-science","display_name":"Computer science","score":0.3353423476219177},{"id":"https://openalex.org/keywords/optics","display_name":"Optics","score":0.32558631896972656},{"id":"https://openalex.org/keywords/physics","display_name":"Physics","score":0.3181476593017578},{"id":"https://openalex.org/keywords/antenna","display_name":"Antenna (radio)","score":0.3164949119091034},{"id":"https://openalex.org/keywords/optoelectronics","display_name":"Optoelectronics","score":0.3007606565952301},{"id":"https://openalex.org/keywords/slot-antenna","display_name":"Slot antenna","score":0.21410289406776428},{"id":"https://openalex.org/keywords/engineering","display_name":"Engineering","score":0.2070411741733551},{"id":"https://openalex.org/keywords/telecommunications","display_name":"Telecommunications","score":0.19514566659927368},{"id":"https://openalex.org/keywords/dielectric","display_name":"Dielectric","score":0.12656089663505554}],"concepts":[{"id":"https://openalex.org/C110367647","wikidata":"https://www.wikidata.org/wiki/Q497166","display_name":"Metamaterial","level":2,"score":0.7065852284431458},{"id":"https://openalex.org/C189039984","wikidata":"https://www.wikidata.org/wiki/Q8225412","display_name":"Directivity","level":3,"score":0.5281151533126831},{"id":"https://openalex.org/C129828019","wikidata":"https://www.wikidata.org/wiki/Q12326787","display_name":"Metamaterial antenna","level":5,"score":0.4950358271598816},{"id":"https://openalex.org/C168651791","wikidata":"https://www.wikidata.org/wiki/Q211569","display_name":"Permittivity","level":3,"score":0.4624597728252411},{"id":"https://openalex.org/C64671776","wikidata":"https://www.wikidata.org/wiki/Q769152","display_name":"Directional antenna","level":3,"score":0.4147842526435852},{"id":"https://openalex.org/C24326235","wikidata":"https://www.wikidata.org/wiki/Q126095","display_name":"Electronic engineering","level":1,"score":0.3867322504520416},{"id":"https://openalex.org/C192562407","wikidata":"https://www.wikidata.org/wiki/Q228736","display_name":"Materials science","level":0,"score":0.3735559582710266},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.3353423476219177},{"id":"https://openalex.org/C120665830","wikidata":"https://www.wikidata.org/wiki/Q14620","display_name":"Optics","level":1,"score":0.32558631896972656},{"id":"https://openalex.org/C121332964","wikidata":"https://www.wikidata.org/wiki/Q413","display_name":"Physics","level":0,"score":0.3181476593017578},{"id":"https://openalex.org/C21822782","wikidata":"https://www.wikidata.org/wiki/Q131214","display_name":"Antenna (radio)","level":2,"score":0.3164949119091034},{"id":"https://openalex.org/C49040817","wikidata":"https://www.wikidata.org/wiki/Q193091","display_name":"Optoelectronics","level":1,"score":0.3007606565952301},{"id":"https://openalex.org/C109026120","wikidata":"https://www.wikidata.org/wiki/Q2369099","display_name":"Slot antenna","level":4,"score":0.21410289406776428},{"id":"https://openalex.org/C127413603","wikidata":"https://www.wikidata.org/wiki/Q11023","display_name":"Engineering","level":0,"score":0.2070411741733551},{"id":"https://openalex.org/C76155785","wikidata":"https://www.wikidata.org/wiki/Q418","display_name":"Telecommunications","level":1,"score":0.19514566659927368},{"id":"https://openalex.org/C133386390","wikidata":"https://www.wikidata.org/wiki/Q184996","display_name":"Dielectric","level":2,"score":0.12656089663505554}],"mesh":[],"locations_count":2,"locations":[{"id":"doi:10.1109/access.2022.3157634","is_oa":true,"landing_page_url":"https://doi.org/10.1109/access.2022.3157634","pdf_url":"https://ieeexplore.ieee.org/ielx7/6287639/9668973/09729873.pdf","source":{"id":"https://openalex.org/S2485537415","display_name":"IEEE Access","issn_l":"2169-3536","issn":["2169-3536"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310319808","host_organization_name":"Institute of Electrical and Electronics Engineers","host_organization_lineage":["https://openalex.org/P4310319808"],"host_organization_lineage_names":["Institute of Electrical and Electronics Engineers"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"IEEE Access","raw_type":"journal-article"},{"id":"pmh:oai:doaj.org/article:f971a2c46bc6458ea716574f40cd8e38","is_oa":true,"landing_page_url":"https://doaj.org/article/f971a2c46bc6458ea716574f40cd8e38","pdf_url":null,"source":{"id":"https://openalex.org/S4306401280","display_name":"DOAJ (DOAJ: Directory of Open Access Journals)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"host_organization":null,"host_organization_name":null,"host_organization_lineage":[],"host_organization_lineage_names":[],"type":"repository"},"license":"cc-by-sa","license_id":"https://openalex.org/licenses/cc-by-sa","version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"IEEE Access, Vol 10, Pp 27381-27403 (2022)","raw_type":"article"}],"best_oa_location":{"id":"doi:10.1109/access.2022.3157634","is_oa":true,"landing_page_url":"https://doi.org/10.1109/access.2022.3157634","pdf_url":"https://ieeexplore.ieee.org/ielx7/6287639/9668973/09729873.pdf","source":{"id":"https://openalex.org/S2485537415","display_name":"IEEE Access","issn_l":"2169-3536","issn":["2169-3536"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310319808","host_organization_name":"Institute of Electrical and Electronics Engineers","host_organization_lineage":["https://openalex.org/P4310319808"],"host_organization_lineage_names":["Institute of Electrical and Electronics Engineers"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"IEEE Access","raw_type":"journal-article"},"sustainable_development_goals":[{"id":"https://metadata.un.org/sdg/7","score":0.5600000023841858,"display_name":"Affordable and clean energy"}],"awards":[{"id":"https://openalex.org/G3744139634","display_name":null,"funder_award_id":"217771","funder_id":"https://openalex.org/F4320321020","funder_display_name":"Icelandic Centre for Research"},{"id":"https://openalex.org/G4876521612","display_name":null,"funder_award_id":"2018/31/B/ST7/02369","funder_id":"https://openalex.org/F4320322511","funder_display_name":"Narodowe Centrum Nauki"},{"id":"https://openalex.org/G6374865206","display_name":null,"funder_award_id":"Grant 217771","funder_id":"https://openalex.org/F4320321020","funder_display_name":"Icelandic Centre for Research"},{"id":"https://openalex.org/G8750576860","display_name":null,"funder_award_id":"217771","funder_id":"https://openalex.org/F4320326825","funder_display_name":"Rann\u00eds"}],"funders":[{"id":"https://openalex.org/F4320321020","display_name":"Icelandic Centre for Research","ror":"https://ror.org/03srneg48"},{"id":"https://openalex.org/F4320322511","display_name":"Narodowe Centrum Nauki","ror":"https://ror.org/03ha2q922"},{"id":"https://openalex.org/F4320326825","display_name":"Rann\u00eds","ror":null}],"has_content":{"grobid_xml":true,"pdf":true},"content_urls":{"pdf":"https://content.openalex.org/works/W4226532731.pdf","grobid_xml":"https://content.openalex.org/works/W4226532731.grobid-xml"},"referenced_works_count":156,"referenced_works":["https://openalex.org/W75536252","https://openalex.org/W616848470","https://openalex.org/W1484738750","https://openalex.org/W1553723410","https://openalex.org/W1606702690","https://openalex.org/W1920146223","https://openalex.org/W1971775658","https://openalex.org/W1979061596","https://openalex.org/W1984668271","https://openalex.org/W1988506966","https://openalex.org/W1994620623","https://openalex.org/W1994986015","https://openalex.org/W1999152086","https://openalex.org/W2007210363","https://openalex.org/W2015408750","https://openalex.org/W2017985867","https://openalex.org/W2019732966","https://openalex.org/W2022324759","https://openalex.org/W2027652501","https://openalex.org/W2028385508","https://openalex.org/W2032125480","https://openalex.org/W2032685105","https://openalex.org/W2037629350","https://openalex.org/W2041967476","https://openalex.org/W2043731514","https://openalex.org/W2045305845","https://openalex.org/W2047916953","https://openalex.org/W2049744622","https://openalex.org/W2052501935","https://openalex.org/W2053419099","https://openalex.org/W2059801449","https://openalex.org/W2064240847","https://openalex.org/W2066596632","https://openalex.org/W2069063575","https://openalex.org/W2071542047","https://openalex.org/W2077402815","https://openalex.org/W2089730168","https://openalex.org/W2093133451","https://openalex.org/W2096834981","https://openalex.org/W2097790796","https://openalex.org/W2112567048","https://openalex.org/W2115178087","https://openalex.org/W2115457083","https://openalex.org/W2116761073","https://openalex.org/W2117826288","https://openalex.org/W2137696405","https://openalex.org/W2139201764","https://openalex.org/W2145078790","https://openalex.org/W2148020016","https://openalex.org/W2153039616","https://openalex.org/W2164543574","https://openalex.org/W2167067282","https://openalex.org/W2171111701","https://openalex.org/W2174979207","https://openalex.org/W2208454446","https://openalex.org/W2263098043","https://openalex.org/W2274670413","https://openalex.org/W2277198174","https://openalex.org/W2280783756","https://openalex.org/W2292941061","https://openalex.org/W2294709958","https://openalex.org/W2301987149","https://openalex.org/W2330548931","https://openalex.org/W2344304319","https://openalex.org/W2345721025","https://openalex.org/W2388940869","https://openalex.org/W2404287298","https://openalex.org/W2416709089","https://openalex.org/W2519235930","https://openalex.org/W2531318585","https://openalex.org/W2550691123","https://openalex.org/W2561160389","https://openalex.org/W2573931557","https://openalex.org/W2591629462","https://openalex.org/W2612260312","https://openalex.org/W2615748258","https://openalex.org/W2619596096","https://openalex.org/W2620670073","https://openalex.org/W2621237062","https://openalex.org/W2635711016","https://openalex.org/W2726170932","https://openalex.org/W2753510226","https://openalex.org/W2755878227","https://openalex.org/W2766302103","https://openalex.org/W2766725510","https://openalex.org/W2777969670","https://openalex.org/W2783142341","https://openalex.org/W2783849889","https://openalex.org/W2790640334","https://openalex.org/W2791806103","https://openalex.org/W2794670137","https://openalex.org/W2796184215","https://openalex.org/W2807601737","https://openalex.org/W2808104999","https://openalex.org/W2826680106","https://openalex.org/W2884704235","https://openalex.org/W2885633511","https://openalex.org/W2889195191","https://openalex.org/W2889646459","https://openalex.org/W2890879540","https://openalex.org/W2891764681","https://openalex.org/W2895100801","https://openalex.org/W2897659448","https://openalex.org/W2898185237","https://openalex.org/W2905236139","https://openalex.org/W2906254524","https://openalex.org/W2906844521","https://openalex.org/W2908400817","https://openalex.org/W2910324200","https://openalex.org/W2910601864","https://openalex.org/W2912968289","https://openalex.org/W2916336893","https://openalex.org/W2927774427","https://openalex.org/W2929872551","https://openalex.org/W2944501463","https://openalex.org/W2949948661","https://openalex.org/W2953890248","https://openalex.org/W2955748273","https://openalex.org/W2962637330","https://openalex.org/W2962887521","https://openalex.org/W2969665154","https://openalex.org/W2972434105","https://openalex.org/W2973407914","https://openalex.org/W2975019022","https://openalex.org/W2977797663","https://openalex.org/W2978169194","https://openalex.org/W3000275184","https://openalex.org/W3001842515","https://openalex.org/W3005009408","https://openalex.org/W3005117678","https://openalex.org/W3005413177","https://openalex.org/W3006548891","https://openalex.org/W3007868543","https://openalex.org/W3008382855","https://openalex.org/W3009896700","https://openalex.org/W3015880906","https://openalex.org/W3022465139","https://openalex.org/W3043524238","https://openalex.org/W3047098494","https://openalex.org/W3082841903","https://openalex.org/W3087807997","https://openalex.org/W3087980013","https://openalex.org/W3090783965","https://openalex.org/W3091063916","https://openalex.org/W3094169683","https://openalex.org/W3095796700","https://openalex.org/W3110246730","https://openalex.org/W3116354294","https://openalex.org/W3157608150","https://openalex.org/W3159737431","https://openalex.org/W3174932526","https://openalex.org/W3181358638","https://openalex.org/W4200296366","https://openalex.org/W4205695817","https://openalex.org/W4206998488","https://openalex.org/W4239888464"],"related_works":["https://openalex.org/W130728486","https://openalex.org/W2100895417","https://openalex.org/W2123492791","https://openalex.org/W2376427179","https://openalex.org/W1439671135","https://openalex.org/W1495543883","https://openalex.org/W2235323171","https://openalex.org/W3092138006","https://openalex.org/W4387537284","https://openalex.org/W438005229"],"abstract_inverted_index":{"Metamaterials":[0],"(MTMs)":[1],"are":[2,51,85,131,209,258],"artificially":[3],"engineered":[4],"materials":[5],"with":[6,166,192],"unique":[7],"electromagnetic":[8,24,56],"properties":[9,39,185],"not":[10],"occurring":[11],"in":[12,66,75,79,88,97,108,133,141,211,213,280],"natural":[13],"materials.":[14],"MTMs":[15,67,84,187,191],"have":[16,68],"gained":[17],"considerable":[18],"attention":[19],"owing":[20],"to":[21,53,73,101,164,219,260,274],"their":[22,170,217],"exotic":[23],"characteristics":[25],"such":[26,44],"as":[27,45],"negative":[28,34,253],"permittivity":[29],"and":[30,47,50,63,115,120,123,150,206,234,252],"permeability,":[31],"thereby":[32],"a":[33,161,174,224],"refraction":[35],"index.":[36],"These":[37],"extraordinary":[38],"enable":[40],"many":[41],"practical":[42],"applications":[43],"super-lenses,":[46],"cloaking":[48],"technology,":[49],"used":[52],"design":[54],"different":[55,242],"devices":[57],"like":[58],"filters,":[59],"polarization":[60],"converters,":[61],"sensors,":[62],"absorbers.":[64],"Advances":[65],"made":[69],"new":[70],"application":[71],"fields":[72],"emerge":[74],"communication":[76,136],"subsystems,":[77],"especially":[78],"the":[80,92,98,103,118,125,143,148,152,167,183,214,221,281],"field":[81],"of":[82,105,110,177,186,195,216,223,227,268],"antennas.":[83,229],"usually":[86],"arranged":[87],"front":[89],"or":[90,95],"above":[91],"radiating":[93],"element,":[94],"incorporated":[96],"same":[99],"substrate":[100],"improve":[102],"performance":[104],"planar":[106,228,261],"antennas,":[107],"terms":[109],"improving":[111,142],"directivity,":[112],"gain,":[113],"bandwidth,":[114],"efficiency,":[116],"reducing":[117,147],"size":[119],"mutual":[121],"coupling,":[122],"deflecting":[124],"radiation":[126],"characteristics.":[127],"High":[128],"gain":[129,179,222,264],"antennas":[130,262,275],"demanded":[132],"modern":[134],"wireless":[135],"systems.":[137],"Their":[138],"importance":[139],"is":[140,188,238],"signal":[144],"strength":[145],"by":[146,240],"interference":[149],"alleviating":[151],"free":[153],"space":[154],"path":[155],"loss.":[156],"This":[157],"review":[158,270],"paper":[159],"provides":[160],"brief":[162],"introduction":[163],"MTMs,":[165],"focus":[168],"on":[169,182],"operating":[171],"principles.":[172],"Furthermore,":[173],"detailed":[175],"study":[176],"antenna":[178],"enhancement":[180],"based":[181],"various":[184],"carried":[189],"out.":[190],"low":[193,231],"values":[194],"constitutive":[196],"parameters;":[197],"zero-index":[198],"material":[199,202],"(ZIM),":[200],"low-index":[201],"(LIM),":[203],"epsilon-near-zero":[204],"(ENZ),":[205],"mu-near-zero":[207],"(MNZ)":[208],"discussed":[210],"detail":[212],"context":[215],"capability":[218],"enhance":[220],"broad":[225],"class":[226],"The":[230,266],"impedance":[232],"property":[233],"lensing":[235],"property,":[236],"which":[237],"achieved":[239],"three":[241],"characteristics:":[243],"high":[244],"refractive":[245,249,254],"index":[246,250,255],"(HRI),":[247],"gradient":[248],"(GRIN),":[251],"(NRI)":[256],"materials,":[257],"loaded":[259],"for":[263],"enhancement.":[265],"scope":[267],"this":[269],"has":[271],"been":[272],"limited":[273],"that":[276],"were":[277],"experimentally":[278],"validated":[279],"respective":[282],"source":[283],"papers.":[284]},"counts_by_year":[{"year":2026,"cited_by_count":6},{"year":2025,"cited_by_count":17},{"year":2024,"cited_by_count":22},{"year":2023,"cited_by_count":10},{"year":2022,"cited_by_count":4}],"updated_date":"2026-06-11T09:08:48.828518","created_date":"2025-10-10T00:00:00"}
