{"id":63566,"date":"2022-05-20T11:10:43","date_gmt":"2022-05-20T16:10:43","guid":{"rendered":"https:\/\/www.bjultrasonic.com\/is-there-a-possibility-of-using-piezoceramic-actuators-at-cryogenic-temperatures\/"},"modified":"2025-01-27T06:14:38","modified_gmt":"2025-01-27T11:14:38","slug":"is-there-a-possibility-of-using-piezoceramic-actuators-at-cryogenic-temperatures","status":"publish","type":"post","link":"https:\/\/www.bjultrasonic.com\/cs\/is-there-a-possibility-of-using-piezoceramic-actuators-at-cryogenic-temperatures\/","title":{"rendered":"Piezoelektrick\u00e9 aktu\u00e1tory p\u0159i kryogenn\u00edch teplot\u00e1ch?"},"content":{"rendered":"<p>Piezoelektrick\u00e9 aktu\u00e1tory nach\u00e1zej\u00ed \u0161irok\u00e9 uplatn\u011bn\u00ed v r\u016fzn\u00fdch oblastech, od p\u0159esn\u00e9ho polohov\u00e1n\u00ed a\u017e po generov\u00e1n\u00ed ultrazvuku.  Jejich funk\u010dnost je v\u0161ak siln\u011b z\u00e1visl\u00e1 na teplot\u011b.  Ot\u00e1zkou, kter\u00e1 si zaslou\u017e\u00ed podrobn\u011bj\u0161\u00ed prozkoum\u00e1n\u00ed, je jejich chov\u00e1n\u00ed a pou\u017eitelnost v kryogenn\u00edch podm\u00ednk\u00e1ch, tedy p\u0159i teplot\u00e1ch v\u00fdrazn\u011b pod bodem mrazu.  Tento \u010dl\u00e1nek se zam\u011b\u0159\u00ed na mo\u017enost vyu\u017eit\u00ed piezoelektrick\u00fdch aktu\u00e1tor\u016f v kryogenn\u00edm prost\u0159ed\u00ed a zv\u00e1\u017e\u00ed souvisej\u00edc\u00ed v\u00fdzvy a omezen\u00ed.<\/p>\n<p>Vliv n\u00edzk\u00fdch teplot na piezoelektrick\u00e9 vlastnosti<\/p>\n<p>Piezoelektrick\u00fd efekt, na n\u011bm\u017e je funkce t\u011bchto aktu\u00e1tor\u016f zalo\u017eena, je citliv\u00fd na zm\u011bny teploty.  S klesaj\u00edc\u00ed teplotou se obvykle m\u011bn\u00ed piezoelektrick\u00e9 konstanty materi\u00e1lu, co\u017e vede ke zm\u011bn\u011b generovan\u00e9 s\u00edly a posunut\u00ed.  Tento vliv se li\u0161\u00ed v z\u00e1vislosti na pou\u017eit\u00e9m materi\u00e1lu.  N\u011bkter\u00e9 materi\u00e1ly vykazuj\u00ed relativn\u011b stabiln\u00ed chov\u00e1n\u00ed v \u0161irok\u00e9m teplotn\u00edm rozmez\u00ed, zat\u00edmco jin\u00e9 podl\u00e9haj\u00ed v\u00fdrazn\u00fdm zm\u011bn\u00e1m sv\u00fdch vlastnost\u00ed p\u0159i n\u00edzk\u00fdch teplot\u00e1ch.  Krom\u011b piezoelektrick\u00fdch konstant se m\u011bn\u00ed i dal\u0161\u00ed parametry, jako je mechanick\u00e1 pevnost a dielektrick\u00e1 konstanta.  Tyto zm\u011bny mohou ovlivnit spolehlivost a \u017eivotnost aktu\u00e1toru v kryogenn\u00edch aplikac\u00edch.<\/p>\n<table class=\"table table-striped table-bordered\">\n<thead>\n<tr>\n<th>Materi\u00e1l<\/th>\n<th>Piezoelektrick\u00e1 konstanta (d33) p\u0159i 25\u00b0C [pC\/N]<\/th>\n<th>Zm\u011bna d33 p\u0159i -196\u00b0C [%]<\/th>\n<th>Mechanick\u00e1 pevnost p\u0159i -196\u00b0C<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>PZT-5A<\/td>\n<td>370<\/td>\n<td>-15<\/td>\n<td>Zv\u00fd\u0161en\u00e1<\/td>\n<\/tr>\n<tr>\n<td>PZT-4<\/td>\n<td>274<\/td>\n<td>-10<\/td>\n<td>Zv\u00fd\u0161en\u00e1<\/td>\n<\/tr>\n<tr>\n<td>PMN-PT<\/td>\n<td>1500<\/td>\n<td>-25<\/td>\n<td>Relativn\u011b stabiln\u00ed<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Mo\u017enosti a omezen\u00ed pou\u017eit\u00ed v kryogenn\u00edch aplikac\u00edch<\/p>\n<p>Pou\u017eit\u00ed piezoelektrick\u00fdch aktu\u00e1tor\u016f v kryogenn\u00edch podm\u00ednk\u00e1ch je omezeno p\u0159edev\u0161\u00edm zm\u011bnami jejich vlastnost\u00ed p\u0159i n\u00edzk\u00fdch teplot\u00e1ch.  Zv\u00fd\u0161en\u00e1 mechanick\u00e1 pevnost n\u011bkter\u00fdch materi\u00e1l\u016f m\u016f\u017ee b\u00fdt v\u00fdhodn\u00e1 pro aplikace vy\u017eaduj\u00edc\u00ed vysokou odolnost proti mechanick\u00e9mu nam\u00e1h\u00e1n\u00ed.  Av\u0161ak sn\u00ed\u017een\u00ed piezoelektrick\u00fdch konstant m\u016f\u017ee v\u00e9st ke sn\u00ed\u017een\u00ed \u00fa\u010dinnosti aktu\u00e1toru.  Nav\u00edc je nutn\u00e9 zohlednit vliv teplotn\u00edch gradient\u016f a teplotn\u00edch \u0161ok\u016f, kter\u00e9 mohou v\u00e9st k po\u0161kozen\u00ed aktu\u00e1toru.  D\u016fle\u017eit\u00fdm faktorem je i volba vhodn\u00e9ho materi\u00e1lu a konstrukce aktu\u00e1toru, kter\u00e1 minimalizuje negativn\u00ed dopady n\u00edzk\u00fdch teplot.  Pro dosa\u017een\u00ed optim\u00e1ln\u00edch v\u00fdsledk\u016f je \u010dasto nutn\u00e9 pou\u017e\u00edt speci\u00e1ln\u00ed materi\u00e1ly a konstruk\u010dn\u00ed \u0159e\u0161en\u00ed.<\/p>\n<p>Modifikace a optimalizace pro kryogenn\u00ed prost\u0159ed\u00ed<\/p>\n<p>V\u00fdzkum se zam\u011b\u0159uje na v\u00fdvoj nov\u00fdch materi\u00e1l\u016f a konstruk\u010dn\u00edch \u0159e\u0161en\u00ed, kter\u00e1 by zlep\u0161ila funk\u010dnost piezoelektrick\u00fdch aktu\u00e1tor\u016f v kryogenn\u00edch podm\u00ednk\u00e1ch.  Pat\u0159\u00ed sem nap\u0159\u00edklad pou\u017eit\u00ed kompozitn\u00edch materi\u00e1l\u016f, optimalizace tvaru aktu\u00e1toru a pou\u017eit\u00ed speci\u00e1ln\u00edch povlak\u016f.  V n\u011bkter\u00fdch p\u0159\u00edpadech se vyu\u017e\u00edv\u00e1 pre-p\u0159edp\u011bt\u00ed aktu\u00e1toru, aby se kompenzovaly zm\u011bny jeho vlastnost\u00ed p\u0159i n\u00edzk\u00fdch teplot\u00e1ch.  V\u00fdsledkem tohoto v\u00fdzkumu jsou aktu\u00e1tory s vylep\u0161en\u00fdmi vlastnostmi pro pou\u017eit\u00ed v kryogenn\u00edch aplikac\u00edch, nap\u0159\u00edklad v oblasti kryogenn\u00edch mikroskop\u016f nebo v experimentech s n\u00edzk\u00fdmi teplotami.<\/p>\n<p>Z\u00e1v\u011br<\/p>\n<p>Pou\u017eit\u00ed piezoelektrick\u00fdch aktu\u00e1tor\u016f v kryogenn\u00edch podm\u00ednk\u00e1ch je mo\u017en\u00e9, av\u0161ak vy\u017eaduje d\u016fkladn\u00e9 zv\u00e1\u017een\u00ed vlivu n\u00edzk\u00fdch teplot na jejich vlastnosti.  Volba materi\u00e1lu a konstrukce aktu\u00e1toru je kl\u00ed\u010dov\u00e1 pro dosa\u017een\u00ed optim\u00e1ln\u00edho v\u00fdkonu a spolehlivosti.  Pokra\u010duj\u00edc\u00ed v\u00fdzkum v oblasti nov\u00fdch materi\u00e1l\u016f a konstruk\u010dn\u00edch \u0159e\u0161en\u00ed otev\u00edr\u00e1 nov\u00e9 mo\u017enosti pro vyu\u017eit\u00ed piezoelektrick\u00fdch aktu\u00e1tor\u016f v tomto n\u00e1ro\u010dn\u00e9m prost\u0159ed\u00ed.  P\u0159esto\u017ee existuj\u00ed v\u00fdzvy, potenci\u00e1ln\u00ed aplikace v kryogenice jsou zna\u010dn\u00e9 a od\u016fvod\u0148uj\u00ed dal\u0161\u00ed intenzivn\u00ed v\u00fdzkum v t\u00e9to oblasti.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Piezoelektrick\u00e9 aktu\u00e1tory nach\u00e1zej\u00ed \u0161irok\u00e9 uplatn\u011bn\u00ed v r\u016fzn\u00fdch oblastech, od p\u0159esn\u00e9ho polohov\u00e1n\u00ed a\u017e po generov\u00e1n\u00ed ultrazvuku. Jejich funk\u010dnost je v\u0161ak siln\u011b z\u00e1visl\u00e1 na teplot\u011b. Ot\u00e1zkou, kter\u00e1 si zaslou\u017e\u00ed podrobn\u011bj\u0161\u00ed prozkoum\u00e1n\u00ed, je jejich chov\u00e1n\u00ed a pou\u017eitelnost v kryogenn\u00edch podm\u00ednk\u00e1ch, tedy p\u0159i teplot\u00e1ch v\u00fdrazn\u011b pod bodem mrazu. Tento \u010dl\u00e1nek se zam\u011b\u0159\u00ed na mo\u017enost vyu\u017eit\u00ed piezoelektrick\u00fdch aktu\u00e1tor\u016f v kryogenn\u00edm<\/p>\n","protected":false},"author":1,"featured_media":587,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6415],"tags":[],"class_list":["post-63566","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\/63566","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=63566"}],"version-history":[{"count":0,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/posts\/63566\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/media\/587"}],"wp:attachment":[{"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/media?parent=63566"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/categories?post=63566"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/tags?post=63566"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}