{"id":62921,"date":"2022-09-13T03:30:03","date_gmt":"2022-09-13T08:30:03","guid":{"rendered":"https:\/\/www.bjultrasonic.com\/piezo-ceramics-how-to-define-an-electric-field\/"},"modified":"2025-01-27T06:14:53","modified_gmt":"2025-01-27T11:14:53","slug":"piezo-ceramics-how-to-define-an-electric-field","status":"publish","type":"post","link":"https:\/\/www.bjultrasonic.com\/cs\/piezo-ceramics-how-to-define-an-electric-field\/","title":{"rendered":"Piezokera: Definice elektrick\u00e9ho pole v praxi"},"content":{"rendered":"<p>Piezokrystaly, a speci\u00e1ln\u011b piezo keramika, p\u0159edstavuj\u00ed fascinuj\u00edc\u00ed materi\u00e1l s unik\u00e1tn\u00ed schopnost\u00ed p\u0159em\u011b\u0148ovat mechanickou energii na energii elektrickou a naopak.  Definice elektrick\u00e9ho pole v piezo keramice v\u0161ak nen\u00ed trivi\u00e1ln\u00ed a vy\u017eaduje pochopen\u00ed jak jejich struktury, tak i princip\u016f piezoelektrick\u00e9ho jevu.<\/p>\n<h3>Mikrostruktura a piezoelektrick\u00fd efekt<\/h3>\n<p>Piezo keramika je polykrystalick\u00fd materi\u00e1l slo\u017een\u00fd z miliard mikroskopick\u00fdch krystal\u016f, z nich\u017e ka\u017ed\u00fd vykazuje piezoelektrick\u00e9 vlastnosti.  Tyto vlastnosti vypl\u00fdvaj\u00ed z asymetrick\u00e9 struktury krystalov\u00e9 m\u0159\u00ed\u017eky.  V nep\u0159\u00edtomnosti vn\u011bj\u0161\u00edho mechanick\u00e9ho nap\u011bt\u00ed je elektrick\u00fd dip\u00f3l v ka\u017ed\u00e9m krystalu n\u00e1hodn\u011b orientov\u00e1n, a v\u00fdsledn\u00fd makroskopick\u00fd elektrick\u00fd dip\u00f3l je nulov\u00fd.  Aplikac\u00ed mechanick\u00e9ho tlaku (nap\u0159. stla\u010den\u00ed) se v\u0161ak tyto dip\u00f3ly \u010d\u00e1ste\u010dn\u011b uspo\u0159\u00e1daj\u00ed a vznikne makroskopick\u00fd elektrick\u00fd dip\u00f3l, co\u017e se projev\u00ed jako vznik elektrick\u00e9ho pole p\u0159es materi\u00e1l.  Naopak, aplikac\u00ed elektrick\u00e9ho pole dojde k deformaci krystalov\u00e9 m\u0159\u00ed\u017eky a ke zm\u011bn\u011b rozm\u011br\u016f materi\u00e1lu.<\/p>\n<h3>Metody definov\u00e1n\u00ed elektrick\u00e9ho pole<\/h3>\n<p>Definice elektrick\u00e9ho pole v piezo keramice z\u00e1vis\u00ed na kontextu a pou\u017eit\u00e9 metod\u011b m\u011b\u0159en\u00ed.  Nejb\u011b\u017en\u011bj\u0161\u00ed p\u0159\u00edstupy zahrnuj\u00ed:<\/p>\n<ul>\n<li>\n<p><strong>M\u011b\u0159en\u00ed nap\u011bt\u00ed:<\/strong> Nejjednodu\u0161\u0161\u00ed metodou je m\u011b\u0159en\u00ed nap\u011bt\u00ed mezi dv\u011bma elektrodami nanesen\u00fdmi na povrch piezo keramiky.  Vznikl\u00e9 nap\u011bt\u00ed je p\u0159\u00edmo \u00fam\u011brn\u00e9 intenzit\u011b elektrick\u00e9ho pole a lze jej snadno zm\u011b\u0159it pomoc\u00ed voltmetru.  Tato metoda je vhodn\u00e1 pro statick\u00e9 nebo pomalu se m\u011bn\u00edc\u00ed pole.<\/p>\n<\/li>\n<li>\n<p><strong>M\u011b\u0159en\u00ed proudu:<\/strong>  Pro dynamick\u00e9 procesy, jako je generov\u00e1n\u00ed ultrazvuku, je vhodn\u011bj\u0161\u00ed m\u011b\u0159en\u00ed elektrick\u00e9ho proudu proch\u00e1zej\u00edc\u00edho piezo keramikou.  Proud je \u00fam\u011brn\u00fd \u010dasov\u00e9 zm\u011bn\u011b elektrick\u00e9ho toku a poskytuje informace o dynamice elektrick\u00e9ho pole.<\/p>\n<\/li>\n<li>\n<p><strong>Simulace pomoc\u00ed kone\u010dn\u00fdch prvk\u016f:<\/strong> Pro slo\u017eit\u011bj\u0161\u00ed geometrie a okrajov\u00e9 podm\u00ednky je nutn\u00e9 pou\u017e\u00edt numerick\u00e9 simulace, nap\u0159. metodu kone\u010dn\u00fdch prvk\u016f.  Tyto simulace umo\u017e\u0148uj\u00ed p\u0159esn\u011bj\u0161\u00ed ur\u010den\u00ed rozlo\u017een\u00ed elektrick\u00e9ho pole uvnit\u0159 piezo keramiky a jeho z\u00e1vislosti na geometrii, materi\u00e1lov\u00fdch parametrech a vn\u011bj\u0161\u00edch podm\u00ednk\u00e1ch.<\/p>\n<\/li>\n<\/ul>\n<h3>Faktory ovliv\u0148uj\u00edc\u00ed elektrick\u00e9 pole<\/h3>\n<p>Intenzita elektrick\u00e9ho pole v piezo keramice nen\u00ed konstantn\u00ed a z\u00e1vis\u00ed na \u0159ad\u011b faktor\u016f:<\/p>\n<table class=\"table table-striped table-bordered\">\n<thead>\n<tr>\n<th>Faktor<\/th>\n<th>Vliv na elektrick\u00e9 pole<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Mechanick\u00e9 nap\u011bt\u00ed<\/td>\n<td>P\u0159\u00edm\u00e1 \u00fam\u011bra: v\u011bt\u0161\u00ed nap\u011bt\u00ed vede k siln\u011bj\u0161\u00edmu poli<\/td>\n<\/tr>\n<tr>\n<td>Aplikovan\u00e9 nap\u011bt\u00ed<\/td>\n<td>P\u0159\u00edm\u00e1 \u00fam\u011bra: vy\u0161\u0161\u00ed nap\u011bt\u00ed vede k siln\u011bj\u0161\u00edmu poli<\/td>\n<\/tr>\n<tr>\n<td>Teplota<\/td>\n<td>Vliv z\u00e1vis\u00ed na materi\u00e1lu, m\u016f\u017ee v\u00e9st k nelinearit\u00e1m<\/td>\n<\/tr>\n<tr>\n<td>Frekvence (pro AC)<\/td>\n<td>Vliv z\u00e1vis\u00ed na materi\u00e1lov\u00fdch vlastnostech a rezonanci<\/td>\n<\/tr>\n<tr>\n<td>Geometrie vzorku<\/td>\n<td>Ovliv\u0148uje rozlo\u017een\u00ed pole, zejm\u00e9na u slo\u017eit\u00fdch tvar\u016f<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>Aplikace a p\u0159\u00edklady<\/h3>\n<p>Definice a m\u011b\u0159en\u00ed elektrick\u00e9ho pole v piezo keramice jsou kl\u00ed\u010dov\u00e9 pro mnoho aplikac\u00ed, v\u010detn\u011b:<\/p>\n<ul>\n<li><strong>Generov\u00e1n\u00ed ultrazvuku:<\/strong>  V ultrazvukov\u00fdch senzorech a aktorech je elektrick\u00e9 pole pou\u017eito k vyvol\u00e1n\u00ed mechanick\u00fdch vibrac\u00ed piezo keramiky, kter\u00e9 generuj\u00ed ultrazvukov\u00e9 vlny.  P\u0159esn\u00e9 \u0159\u00edzen\u00ed elektrick\u00e9ho pole je z\u00e1sadn\u00ed pro optimalizaci v\u00fdkonu t\u011bchto za\u0159\u00edzen\u00ed.<\/li>\n<li><strong>Piezoelektrick\u00e9 senzory:<\/strong>  V t\u011bchto senzorech se zm\u011bna elektrick\u00e9ho pole m\u011b\u0159\u00ed jako reakce na mechanick\u00fd tlak nebo deformaci.  P\u0159esnost m\u011b\u0159en\u00ed z\u00e1vis\u00ed na spr\u00e1vn\u00e9 definici a kalibraci vztahu mezi mechanick\u00fdm a elektrick\u00fdm polem.<\/li>\n<\/ul>\n<p>Z\u00e1v\u011brem lze \u0159\u00edci, \u017ee definice elektrick\u00e9ho pole v piezo keramice je multidisciplin\u00e1rn\u00ed probl\u00e9m, kter\u00fd zahrnuje materi\u00e1lov\u00e9 v\u011bdy, elektrotechniku a numerick\u00e9 simulace.  Pochopen\u00ed princip\u016f piezoelektrick\u00e9ho jevu a vlivu r\u016fzn\u00fdch faktor\u016f na elektrick\u00e9 pole je kl\u00ed\u010dov\u00e9 pro optimalizaci a v\u00fdvoj aplikac\u00ed vyu\u017e\u00edvaj\u00edc\u00edch piezo keramiku.  P\u0159esn\u00e9 m\u011b\u0159en\u00ed a modelov\u00e1n\u00ed elektrick\u00e9ho pole je nezbytn\u00e9 pro \u0161irok\u00e9 spektrum technologi\u00ed, od l\u00e9ka\u0159sk\u00e9 diagnostiky po pr\u016fmyslovou automatizaci.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Piezokrystaly, a speci\u00e1ln\u011b piezo keramika, p\u0159edstavuj\u00ed fascinuj\u00edc\u00ed materi\u00e1l s unik\u00e1tn\u00ed schopnost\u00ed p\u0159em\u011b\u0148ovat mechanickou energii na energii elektrickou a naopak. Definice elektrick\u00e9ho pole v piezo keramice v\u0161ak nen\u00ed trivi\u00e1ln\u00ed a vy\u017eaduje pochopen\u00ed jak jejich struktury, tak i princip\u016f piezoelektrick\u00e9ho jevu. Mikrostruktura a piezoelektrick\u00fd efekt Piezo keramika je polykrystalick\u00fd materi\u00e1l slo\u017een\u00fd z miliard mikroskopick\u00fdch krystal\u016f, z nich\u017e<\/p>\n","protected":false},"author":1,"featured_media":5010,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6415],"tags":[],"class_list":["post-62921","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\/62921","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=62921"}],"version-history":[{"count":0,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/posts\/62921\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/media\/5010"}],"wp:attachment":[{"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/media?parent=62921"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/categories?post=62921"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/tags?post=62921"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}