{"id":61056,"date":"2023-04-21T14:42:11","date_gmt":"2023-04-21T19:42:11","guid":{"rendered":"https:\/\/www.bjultrasonic.com\/how-does-piezoelectricity-work\/"},"modified":"2025-01-27T06:06:18","modified_gmt":"2025-01-27T11:06:18","slug":"how-does-piezoelectricity-work","status":"publish","type":"post","link":"https:\/\/www.bjultrasonic.com\/cs\/how-does-piezoelectricity-work\/","title":{"rendered":"Piezoelekt\u0159ina: Jak funguje tento fascinuj\u00edc\u00ed jev?"},"content":{"rendered":"<p>Piezoelekt\u0159ina je fascinuj\u00edc\u00ed jev, kter\u00fd spojuje mechanickou deformaci krystalick\u00e9 struktury s generov\u00e1n\u00edm elektrick\u00e9ho n\u00e1boje a naopak.  Tento efekt nach\u00e1z\u00ed \u0161irok\u00e9 uplatn\u011bn\u00ed v mnoha oblastech, od zapalova\u010d\u016f a reproduktor\u016f a\u017e po vysoce precizn\u00ed senzory a l\u00e9ka\u0159sk\u00e9 p\u0159\u00edstroje.  Pochopen\u00ed principu piezoelekt\u0159iny vy\u017eaduje nahl\u00e9dnut\u00ed do struktury krystal\u016f a interakce mezi jejich atomy a vn\u011bj\u0161\u00edm tlakem nebo elektrick\u00fdm polem.<\/p>\n<p>Krystalov\u00e1 struktura a polarizace<\/p>\n<p>Piezoelektrick\u00fd efekt se projevuje u materi\u00e1l\u016f s necentrosymetrickou krystalovou strukturou. To znamen\u00e1, \u017ee jejich atomy nejsou symetricky uspo\u0159\u00e1d\u00e1ny kolem st\u0159edu krystalu.  Tato asymetrie je kl\u00ed\u010dov\u00e1 pro vznik piezoelektrick\u00e9ho jevu.  Kdy\u017e je krystal mechanicky stla\u010den nebo nata\u017een, doch\u00e1z\u00ed k posunut\u00ed iont\u016f v krystalov\u00e9 m\u0159\u00ed\u017ece.  Toto posunut\u00ed vytv\u00e1\u0159\u00ed dip\u00f3lov\u00e9 momenty, kter\u00e9 se s\u010d\u00edtaj\u00ed a vytv\u00e1\u0159ej\u00ed makroskopick\u00fd elektrick\u00fd n\u00e1boj na povrchu krystalu.  Naopak, pokud se na krystal p\u0159ilo\u017e\u00ed elektrick\u00e9 pole, dojde k deformaci krystalov\u00e9 m\u0159\u00ed\u017eky v d\u016fsledku elektrostatick\u00fdch sil p\u016fsob\u00edc\u00edch na ionty.<\/p>\n<table class=\"table table-striped table-bordered\">\n<thead>\n<tr>\n<th>Krystalov\u00fd syst\u00e9m<\/th>\n<th>Piezoelektrick\u00fd?<\/th>\n<th>P\u0159\u00edklady materi\u00e1l\u016f<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Trigonal<\/td>\n<td>Ano<\/td>\n<td>K\u0159emen, Turmal\u00edn<\/td>\n<\/tr>\n<tr>\n<td>Tetragon\u00e1ln\u00ed<\/td>\n<td>Ano<\/td>\n<td>Zine\u010dnat\u00fd oxid zirkoni\u010dit\u00fd (PZT)<\/td>\n<\/tr>\n<tr>\n<td>Romboedrick\u00fd<\/td>\n<td>Ano<\/td>\n<td>K\u0159emen<\/td>\n<\/tr>\n<tr>\n<td>Monoklinick\u00fd<\/td>\n<td>Ano<\/td>\n<td>N\u011bkter\u00e9 keramiky<\/td>\n<\/tr>\n<tr>\n<td>Triklinick\u00fd<\/td>\n<td>Ano<\/td>\n<td>N\u011bkter\u00e9 keramiky<\/td>\n<\/tr>\n<tr>\n<td>Kubick\u00fd<\/td>\n<td>Ne<\/td>\n<td>S\u016fl, Diamant<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Druhy piezoelektrick\u00e9ho efektu<\/p>\n<p>Rozli\u0161ujeme dva z\u00e1kladn\u00ed druhy piezoelektrick\u00e9ho efektu: p\u0159\u00edm\u00fd a nep\u0159\u00edm\u00fd.  P\u0159\u00edm\u00fd piezoelektrick\u00fd efekt popisuje generov\u00e1n\u00ed elektrick\u00e9ho n\u00e1boje v d\u016fsledku mechanick\u00e9 deformace.  Nep\u0159\u00edm\u00fd piezoelektrick\u00fd efekt, tak\u00e9 zn\u00e1m\u00fd jako obr\u00e1cen\u00fd piezoelektrick\u00fd efekt, popisuje deformaci krystalu v d\u016fsledku p\u016fsoben\u00ed elektrick\u00e9ho pole.  Oba efekty jsou vz\u00e1jemn\u011b prov\u00e1zan\u00e9 a popisuj\u00ed stejnou podstatu jevu.<\/p>\n<p>Materi\u00e1ly s piezoelektrick\u00fdmi vlastnostmi<\/p>\n<p>Krom\u011b p\u0159\u00edrodn\u00edch materi\u00e1l\u016f, jako je k\u0159emen a turmal\u00edn, se hojn\u011b vyu\u017e\u00edvaj\u00ed syntetick\u00e9 piezoelektrick\u00e9 materi\u00e1ly.  Nejroz\u0161\u00ed\u0159en\u011bj\u0161\u00ed je zine\u010dnat\u00fd oxid zirkoni\u010dit\u00fd (PZT), kter\u00fd vykazuje vysokou piezoelektrickou aktivitu a je snadno tvarovateln\u00fd.  Dal\u0161\u00edmi d\u016fle\u017eit\u00fdmi materi\u00e1ly jsou nap\u0159\u00edklad niob\u00e1t lithn\u00fd (LiNbO3) a titan\u00e1t barnat\u00fd (BaTiO3).  Volba materi\u00e1lu z\u00e1vis\u00ed na specifick\u00e9 aplikaci a po\u017eadovan\u00fdch vlastnostech.<\/p>\n<p>Aplikace piezoelekt\u0159iny<\/p>\n<p>Piezoelektrick\u00e9 materi\u00e1ly nach\u00e1zej\u00ed \u0161irok\u00e9 uplatn\u011bn\u00ed v mnoha oblastech.  Pat\u0159\u00ed mezi n\u011b:<\/p>\n<ul>\n<li><strong>Ultrazvukov\u00e9 senzory a aktu\u00e1tory:<\/strong>  Piezoelektrick\u00e9 krystaly se pou\u017e\u00edvaj\u00ed k generov\u00e1n\u00ed a detekci ultrazvukov\u00fdch vln v l\u00e9ka\u0159sk\u00fdch zobrazovac\u00edch za\u0159\u00edzen\u00edch (ultrazvuk), pr\u016fmyslov\u00fdch senzor\u016f (nap\u0159. m\u011b\u0159en\u00ed tlou\u0161\u0165ky materi\u00e1lu) a v aplikac\u00edch pro \u010di\u0161t\u011bn\u00ed ultrazvukem.  V n\u011bkter\u00fdch p\u0159\u00edpadech, nap\u0159\u00edklad u pokro\u010dil\u00fdch syst\u00e9m\u016f pro zobrazov\u00e1n\u00ed, je nutn\u00e9 zvolit specifick\u00e9 vlastnosti piezoelektrick\u00fdch materi\u00e1l\u016f pro dosa\u017een\u00ed optim\u00e1ln\u00edho v\u00fdkonu.<\/li>\n<li><strong>Zapalova\u010de:<\/strong>  Mechanick\u00e9 stla\u010den\u00ed piezoelektrick\u00e9ho krystalu generuje jiskru, kter\u00e1 zap\u00e1l\u00ed plyn.<\/li>\n<li><strong>Reproduktory a mikrofony:<\/strong>  Piezoelektrick\u00e9 materi\u00e1ly se pou\u017e\u00edvaj\u00ed k p\u0159em\u011bn\u011b elektrick\u00fdch sign\u00e1l\u016f na mechanick\u00e9 vibrace (reproduktor) a naopak (mikrofon).<\/li>\n<li><strong>Senzory tlaku a zrychlen\u00ed:<\/strong>  Piezoelektrick\u00e9 senzory se pou\u017e\u00edvaj\u00ed pro m\u011b\u0159en\u00ed tlaku, vibrac\u00ed a zrychlen\u00ed v r\u016fzn\u00fdch aplikac\u00edch.<\/li>\n<\/ul>\n<p>Z\u00e1v\u011br<\/p>\n<p>Piezoelekt\u0159ina je fascinuj\u00edc\u00ed fyzik\u00e1ln\u00ed jev s mnoha praktick\u00fdmi aplikacemi.  Pochopen\u00ed princip\u016f fungov\u00e1n\u00ed piezoelektrick\u00fdch materi\u00e1l\u016f a jejich vlastnost\u00ed je kl\u00ed\u010dov\u00e9 pro v\u00fdvoj nov\u00fdch technologi\u00ed a inovac\u00ed v r\u016fzn\u00fdch oborech.  Od jednoduch\u00fdch zapalova\u010d\u016f a\u017e po sofistikovan\u00e9 l\u00e9ka\u0159sk\u00e9 p\u0159\u00edstroje, piezoelekt\u0159ina hraje st\u00e1le d\u016fle\u017eit\u011bj\u0161\u00ed roli v modern\u00edm sv\u011bt\u011b.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Piezoelekt\u0159ina je fascinuj\u00edc\u00ed jev, kter\u00fd spojuje mechanickou deformaci krystalick\u00e9 struktury s generov\u00e1n\u00edm elektrick\u00e9ho n\u00e1boje a naopak. Tento efekt nach\u00e1z\u00ed \u0161irok\u00e9 uplatn\u011bn\u00ed v mnoha oblastech, od zapalova\u010d\u016f a reproduktor\u016f a\u017e po vysoce precizn\u00ed senzory a l\u00e9ka\u0159sk\u00e9 p\u0159\u00edstroje. Pochopen\u00ed principu piezoelekt\u0159iny vy\u017eaduje nahl\u00e9dnut\u00ed do struktury krystal\u016f a interakce mezi jejich atomy a vn\u011bj\u0161\u00edm tlakem nebo elektrick\u00fdm polem.<\/p>\n","protected":false},"author":1,"featured_media":23762,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6415],"tags":[],"class_list":["post-61056","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog","prodpage-classic"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/posts\/61056","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/comments?post=61056"}],"version-history":[{"count":0,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/posts\/61056\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/media\/23762"}],"wp:attachment":[{"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/media?parent=61056"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/categories?post=61056"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/tags?post=61056"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}