{"id":32243,"date":"2019-02-04T07:39:12","date_gmt":"2019-02-04T04:39:12","guid":{"rendered":"https:\/\/bilimvegelecek.com.tr\/?p=32243"},"modified":"2019-02-04T07:39:12","modified_gmt":"2019-02-04T04:39:12","slug":"hayal-edin-gercek-olsun-metal-deriler-ve-kullandikca-guclenen-makineler","status":"publish","type":"post","link":"https:\/\/bilimvegelecek.com.tr\/index.php\/2019\/02\/04\/hayal-edin-gercek-olsun-metal-deriler-ve-kullandikca-guclenen-makineler","title":{"rendered":"Hayal edin ger\u00e7ek olsun: Metal deriler ve kulland\u0131k\u00e7a g\u00fc\u00e7lenen makineler"},"content":{"rendered":"

Ge\u00e7ti\u011fimiz haftalarda biri Amerika k\u0131tas\u0131ndan di\u011feri Japonya\u2019dan iki yeni s\u00fcper-malzeme haberi bilim dergilerinin sayfalar\u0131n\u0131 s\u00fcsledi. \u0130kisi de ilham\u0131n\u0131 insan v\u00fccudunun \u00e7e\u015fitli yap\u0131lar\u0131ndan al\u0131yor. Ama ikisi de, en az\u0131ndan kuramsal d\u00fczeyde, kendilerine ba\u015flang\u0131\u00e7 ivmesini kazand\u0131ran bu yap\u0131lar\u0131n \u00e7ok \u00f6tesine ge\u00e7ecek gibi duruyor. ABD-Kanada ortak yap\u0131m\u0131 olandan ba\u015flayal\u0131m…<\/p>\n

D\u00fc\u015f\u00fcn\u00fcn ki deriniz sadece s\u0131cakl\u0131k farklar\u0131n\u0131, bask\u0131y\u0131 ya da titre\u015fimleri de\u011fil ses dalgalar\u0131n\u0131 ve hatta etraf\u0131m\u0131z\u0131 saran manyetik alandaki dalgalanmalar\u0131 da hissedebiliyor. \u00c7izgi roman kahramanlar\u0131n\u0131n sahip oldu\u011fu s\u00fcperg\u00fc\u00e7lere benziyor de\u011fil mi? Elbette Connecticut ve Toronto \u00dcniversitelerinden ara\u015ft\u0131rmac\u0131lar tam da bu \u00f6zelliklere sahip bir t\u00fcr yapay deri \u00fczerinde \u00e7al\u0131\u015fmaya ba\u015flarken ak\u0131llar\u0131ndan ge\u00e7en fantastik senaryolar de\u011fil, kaza sonucu deride hissiyat kayb\u0131 ya\u015fayan insanlar\u0131n ihtiya\u00e7lar\u0131yd\u0131. Fakat geli\u015ftirdikleri malzeme ba\u015flang\u0131\u00e7 deneylerinde o kadar ba\u015far\u0131l\u0131 sonu\u00e7lar verdi ki kullan\u0131m alan\u0131yla ilgili yeni tasar\u0131lar geli\u015ftirmemek elde de\u011fil\u2026 Peki nedir bu malzeme?<\/p>\n

Bir t\u00fcr metal deri diyebiliriz. Islam Mosa, James Rusling ve Abdelsalam Ahmed \u00fc\u00e7l\u00fcs\u00fcn\u00fcn imza att\u0131\u011f\u0131, Advanced Materials<\/em> dergisinin 21 Ocak say\u0131s\u0131nda tan\u0131t\u0131lan malzemenin \u00e7\u0131k\u0131\u015f noktas\u0131 do\u011frudan derinin kendisi. Derinin dokunma hissini taklit etmesi hedeflenen bu sens\u00f6r nispeten basit bir \u00e7al\u0131\u015fma ilkesi \u00fczerine in\u015fa edilmi\u015f. Buna g\u00f6re bak\u0131r tele sar\u0131l\u0131 bir silikon borunun i\u00e7i metrenin milyarda biri b\u00fcy\u00fckl\u00fc\u011f\u00fcnde minik demir oksit par\u00e7ac\u0131klar\u0131ndan (nanopartik\u00fcllerden) olu\u015fan \u00f6zel bir s\u0131v\u0131yla doldurulmu\u015f. Partik\u00fcllerin t\u00fcp\u00fcn i\u00e7 \u00e7eperlerine s\u00fcrt\u00fcnd\u00fck\u00e7e elektrik ak\u0131m\u0131 \u00fcretmesi, silikonu \u00e7evreleyen bak\u0131r telin de bu ak\u0131m\u0131 sinyal olarak alg\u0131lamas\u0131 hedeflenmi\u015f. Nitekim mesela silikon t\u00fcp bask\u0131 yaratan bir uyarana maruz kald\u0131\u011f\u0131nda, nanopartik\u00fcllerin ger\u00e7ekten de belli bir \u015fekilde hareket ederek elektrik sinyallerini de\u011fi\u015ftirdi\u011fi ve bunun bak\u0131r tel taraf\u0131ndan alg\u0131land\u0131\u011f\u0131 bir d\u00fczenek olu\u015fturulabilmi\u015f. Her uyaran\u0131n nanopartik\u00fcllerde yarataca\u011f\u0131 etki farkl\u0131 olaca\u011f\u0131ndan hareketler ve uyaranlar aras\u0131nda \u00e7ok ince ayr\u0131mlar\u0131n yap\u0131labilmesi, hatta ba\u015fta hedeflenmeyen bi\u00e7imde skalaya manyetik alan\u0131n ve ses dalgalar\u0131n\u0131n da eklenmesi m\u00fcmk\u00fcn olmu\u015f. \u00d6yle ki yan\u0131k kurbanlar\u0131 ya da protez uzuv ta\u015f\u0131yanlar gibi deri duyarl\u0131l\u0131\u011f\u0131n\u0131 kaybetmi\u015f ki\u015filerin yeniden \u201chissedebilmelerini\u201d sa\u011flaman\u0131n yan\u0131 s\u0131ra \u00f6rne\u011fin, tehlikeli d\u00fczeyde manyetik alana maruz kalan i\u015f\u00e7iler i\u00e7in bir t\u00fcr giyilebilir uyar\u0131 sistemi olu\u015fturmak gibi \u00f6zel kullan\u0131mlar da tasarlanmaya ba\u015flanm\u0131\u015f. Yapay deri halen deneme a\u015famas\u0131nda, fakat t\u00fcm testlerden ge\u00e7ti\u011finde s\u0131ra sens\u00f6re yass\u0131 bir form kazand\u0131r\u0131p tam anlam\u0131yla deri gibi i\u015flev g\u00f6rmesini sa\u011flama i\u015fine gelecek. O zaman da yukar\u0131daki s\u00fcperg\u00fc\u00e7 senaryolar\u0131 hayal olmaktan belki de \u00e7\u0131kacak, kimbilir\u2026<\/p>\n

Yeni bir makine mant\u0131\u011f\u0131
\n<\/strong>D\u00fcmeni Japonya\u2019dan gelen icada k\u0131rd\u0131\u011f\u0131m\u0131zda kendimizi derinin biraz daha alt\u0131nda, iskelet kaslar\u0131nda buluyoruz. Zira bu seferki makinemiz \u00e7al\u0131\u015fma ilkesini iskelet kaslar\u0131n\u0131n geli\u015fim mekanizmas\u0131ndan al\u0131yor. Ama\u00e7 t\u0131pk\u0131 spor yapt\u0131k\u00e7a g\u00fc\u00e7lenip geli\u015fen kaslar gibi kulland\u0131k\u00e7a g\u00fc\u00e7lenen ve dayan\u0131kl\u0131l\u0131\u011f\u0131 artan bir malzeme ortaya \u00e7\u0131karmak. Hokkaido \u00dcniversitesi\u2019nde \u00e7al\u0131\u015fmalar\u0131n\u0131 s\u00fcrd\u00fcren biliminsanlar\u0131 g\u00f6r\u00fcnen o ki bunu ba\u015fard\u0131 ve sonu\u00e7lar Science<\/em> dergisinin 1 \u015eubat say\u0131s\u0131nda yay\u0131mland\u0131.<\/p>\n

\"\"
\u00c7ift a\u011fl\u0131 hidrojel (i). Gerilme halinde (ii), sert polimerde k\u0131r\u0131lma meydana geliyor. Bu da, renk de\u011fi\u015fimiyle g\u00f6sterilmi\u015f olan mekanoradikalleri a\u00e7\u0131\u011fa \u00e7\u0131kar\u0131yor (iii). Kaynak: Gong J. P. et al., Mechanoresponsive self-growing hydrogels inspired by muscle training, Science, February 1, 2019.<\/figcaption><\/figure>\n

D\u0131\u015far\u0131dan gelen mekanik strese g\u00fc\u00e7lenerek cevap veren, b\u00f6ylece kendini \u00e7evreleyen ko\u015fullara giderek daha g\u00fc\u00e7l\u00fc bi\u00e7imde uyum sa\u011flayan bu malzemenin ad\u0131 \u201c\u00e7ift a\u011fl\u0131 hidrojel\u201d (double-network hidrogel). Bu ifadenin ne anlama geldi\u011fini daha iyi kavramak i\u00e7in dayand\u0131\u011f\u0131 ilkeden, yani kaslar\u0131n geli\u015fim mekanizmas\u0131ndan k\u0131saca bahsetmek gerekiyor. Spor yaparken (\u00f6zellikle de a\u011f\u0131rl\u0131k \u00e7al\u0131\u015f\u0131rken) kasa uygulanan ritmik gerilim mevcut kas liflerinin y\u0131k\u0131ma u\u011frayarak yerlerini yeni ve daha g\u00fc\u00e7l\u00fc\/uzun liflere b\u0131rakmas\u0131yla sonu\u00e7lan\u0131r. Ancak kas bunu yapabilmek i\u00e7in amino asit denen protein yap\u0131ta\u015flar\u0131yla beslenmek durumundad\u0131r \u00e7\u00fcnk\u00fc kas\u0131 olu\u015fturacak lifler bu proteinlerin birle\u015fmesiyle meydana gelir. \u0130\u015fte \u00e7ift a\u011fl\u0131 hidrojel denen malzeme tam olarak bu mekanizman\u0131n bir yans\u0131mas\u0131. Bunun i\u00e7in \u00f6nce %85 su ve biri sert-k\u0131r\u0131lgan, di\u011feri yumu\u015fak-s\u0131k\u0131\u015ft\u0131r\u0131labilir iki \u00e7e\u015fit polimer a\u011f\u0131ndan yap\u0131lm\u0131\u015f bir ana g\u00f6vde tasarlanm\u0131\u015f. Ard\u0131ndan bu iskelet, monomer denen, birle\u015fip polimer olu\u015fturma yetisine sahip par\u00e7ac\u0131klarla dolu bir s\u0131v\u0131 ortama konmu\u015f. Kas ve hidrojel aras\u0131ndaki paralelli\u011fi g\u00f6rebiliyor musunuz? \u00c7ift polimer a\u011f\u0131 ve su bile\u015fiminden olu\u015fan hidrojel iskelet kas\u0131n\u0131, i\u00e7inde bulundu\u011fu monomer dolu s\u0131v\u0131 ortam ise iskelet kaslar\u0131na amino asit ta\u015f\u0131yan kan dola\u015f\u0131m\u0131n\u0131 temsil ediyor.<\/p>\n

\u00c7al\u0131\u015fma raporunda belirtildi\u011fine g\u00f6re hidrojele germe kuvveti uyguland\u0131\u011f\u0131nda -ki bunu m\u00fcmk\u00fcn k\u0131lan hidrojelin yumu\u015fak-s\u0131k\u0131\u015ft\u0131r\u0131labilir yap\u0131daki polimer bile\u015fenidir-, t\u0131pk\u0131 kas liflerinde oldu\u011fu gibi, sert-k\u0131r\u0131lgan yap\u0131daki polimer bile\u015fenin zincirlerinde k\u0131r\u0131lma meydana geliyor. Bu da k\u0131r\u0131k polimer zincirinin ucunda \u201cmekanoradikal\u201d denen bir kimyasal ortaya \u00e7\u0131kar\u0131yor. Mekanoradikaller monomerlerin hidrojel ile b\u00fct\u00fcnle\u015fip polimer a\u011f\u0131na kat\u0131lmalar\u0131n\u0131, b\u00f6ylece malzemenin kelimenin ger\u00e7ek anlam\u0131yla \u201cg\u00fc\u00e7lenmesini\u201d sa\u011fl\u0131yor. \u00d6yle ki germe hareketi artt\u0131k\u00e7a, t\u0131pk\u0131 kas\u0131n g\u00fc\u00e7lenme s\u00fcrecinde oldu\u011fu gibi, y\u0131k\u0131m ve yap\u0131m da art\u0131yor. Nitekim deneylerde hidrojelin 1,5 kat g\u00fc\u00e7lendi\u011fi; sertli\u011finin 23 kat, dolay\u0131s\u0131yla a\u011f\u0131rl\u0131\u011f\u0131n\u0131n %86 oran\u0131nda artt\u0131\u011f\u0131 saptanm\u0131\u015f. Bu m\u00fcthi\u015f malzemenin hedef kitlesini giyilebilir ve destekleyici bir materyale en fazla ihtiya\u00e7 duyan kesim, yani iskelet hasar\u0131 olan ki\u015filer olu\u015fturuyor. Kulland\u0131k\u00e7a g\u00fc\u00e7lenen ve i\u015flevselli\u011fi artan bu malzeme \u015fimdiye kadar al\u0131\u015ft\u0131\u011f\u0131m\u0131z makine mant\u0131\u011f\u0131n\u0131 adeta ba\u015f a\u015fa\u011f\u0131 \u00e7eviriyor.<\/p>\n

Kaynaklar:<\/strong><\/p>\n

1) Kim Krieger, UConn Communication, \u201cArtificial Skin Could Give Superhuman Perception\u201d, 22 Ocak 2019.<\/p>\n

2) Hokkaido University, Research Press Release, \u201cSelf-Growing Materials that Strengthen in Response to Force\u201d, 1 \u015eubat 2019.<\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

Ge\u00e7ti\u011fimiz haftalarda biri Amerika k\u0131tas\u0131ndan di\u011feri Japonya\u2019dan iki yeni s\u00fcper-malzeme haberi bilim dergilerinin sayfalar\u0131n\u0131 s\u00fcsledi. \u0130kisi de ilham\u0131n\u0131 insan v\u00fccudunun \u00e7e\u015fitli yap\u0131lar\u0131ndan al\u0131yor. Ama ikisi de, en az\u0131ndan kuramsal d\u00fczeyde, kendilerine ba\u015flang\u0131\u00e7 ivmesini kazand\u0131ran bu yap\u0131lar\u0131n \u00e7ok \u00f6tesine ge\u00e7ecek gibi duruyor. ABD-Kanada ortak yap\u0131m\u0131 olandan ba\u015flayal\u0131m… D\u00fc\u015f\u00fcn\u00fcn ki deriniz sadece s\u0131cakl\u0131k farklar\u0131n\u0131, bask\u0131y\u0131 ya da […]<\/p>\n","protected":false},"author":184,"featured_media":32244,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[19,3221,31],"tags":[4529,4530,4528],"class_list":["post-32243","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-bilim-gundemi","category-malzeme-bilimleri","category-teknoloji","tag-cift-agli-hidrojel","tag-mikromakineler","tag-yapay-deri"],"acf":[],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t