This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 within the LDRD program.

Polisaj ve Slurry hazırlanması 1. İlk Yakınsak Cila Sistemi hazırlamak (I Bağımsız Yüzey nitial, özellikle C onvergent denilen, S ingle yineleme, R ogue Parçacık-Free polisaj veya Cisr (telaffuz &#39;makas&#39;)) pad ve septum, klima ped yükleyerek 7,17, seyreltilmesi ve kimyasal çamurun stabilize ve filtrasyon sistemi içinde bulamaç içeren. <ol><li> Cisr parlatıcı üzerinde, granit tur tabanı üzerine poliüretan pedi bağlı. Bir kenarı ped uyun ve hava boşlukları en aza indirmek için rakip kenarına doğru yönde basınç uygulayın. Taşkın takımını Trim ve sonra delinme ve gerekirse hava kabarcıklarını çıkarmak için bir jilet ve rulo kullanın. </li><li> İlk kullanımda ve her ~ 100 saat sonraCMP elmas kremi kullanarak pedi, parlatma elmas durumun r (50 mm çap; 0.6 psi basınç uygulanan, 5 dk beklemenin 25 mm boşluk artışlarla her radyal tur yerde; tur dönüşü 25 rpm) akan DI su ile. </li><li> Akan DI suyla, parlatma yineleme arasında, bir in-situ ultrasonik temizleyici (bindirme rotasyon 5 dak ~ her radyal konumda 2 dakika bekleme) ile pedi kalan bulamaç ve cam ürünlerin çıkartılması. </li><li> Benzersiz şeklinde septum ağırlığına, çift taraflı köpük bant ve ardından septum malzeme (örneğin, ön-kesme cam veya diğer non-giyen malzeme) yapışır. Septum malzeme ve ağırlık şekline uygun sarkık bir köpük bandı kesin. Septum tasarımı (şekil ve ağırlık hem) iş parçası ve turun 7,17 farklı boyutları için değiştirir. </li><li> Hacimce karışımı, özellikle (Baume 4 konsantrasyona kadar bulamaç parlatma Hazırlama ~ bir 11 L met 1 kısım seryum oksit parlatma bulamaç ve ~ 9 parça deiyonize (Dİ) sucket). Bir Baume şamandıra kullanarak Baume edin. 9.5 pH değerinin ve ~ özel yüzey 19 içeren 120 ml (1% hacim) eklemek için KOH (10 M) ~ 5 ml ilave edilir. PH ve Baume parlatma her 24 saat yeniden ayarlayın. </li><li> Filtrasyon sistemine hazırlanmış bulamaç ile kova takın. Sonra filtrasyon sistemine istenen CMP parçacık filtreleri yükleyin. Bir kaç saat için filtreleme sistemi içinde bulamaç sirküle olsun. </li><li> Bulamaç Tedbir tanecik boyut dağılımı (örneğin, tek parçacık optik algılama teknikleri kullanılarak) dağıtım kuyruk ucunu sağlamak için yeterli sahte parçacık içermeyen 9,20 olduğunu. </li></ol> İş parçası (yakma ve Engelleme) 2. Hazırlık Parlatma önce, kimyasal hasar 21 taşlama alt yüzeyi kaldırmak için gerekli malzeme kaldırma miktarını azaltmak için alınan-ince öğütülmüş iş parçasını etch. Boy oranı (yani, uzunluk / kalınlık)&gt; 1 ise Ardından, (iş parçası blok0) engelleme ve 22 parlatma sırasında eğilme gelen parçayı önlemek için yeni bir perde düğmesi engelleme (PBB) tekniği kullanılarak. <ol><li> NH4 F: 6 saat boyunca (6: (TTKB) 3x DI su ile seyreltildi 1 tamponlu oksit oyma) çıkarılması ince öğütülmüş iş parçasının (özellikle bir 265 x 265 x 8 mm, 3 kaynaşık silika camı düz) HF ile dolu bir tank içinde Etch iş parçası yüzeyinden cam 10 um. DİKKAT! BOE son derece tehlikelidir; Uygun kişisel koruyucu ekipman (KKE) giyerler. Aşındırma tankından parçasını çıkarın ve agresif DI suyla durulayın ve iş parçasını havaya parça dikey kurumasını bekleyin. </li><li> Karanlık bir odada parlak bir ışık denetimi kullanarak taşlama işlemi sırasında derin hasar için iş parçasını kontrol edin. Hiçbir derin hasar tespit edilirse, başka yeniden taşlama için geri parçayı göndermek, bir sonraki adıma geçin. </li><li> Bir tutkal gun sahayı engelleme ısıtın karşısında üzerine sahanın ~ 95 ºC ve yer damlacıkları (de denir düğmeleri) (~ 0.06 g)9 x 9 dizideki engelleme plakası (26 mm aralıkla 81 düğmeleri). Farklı boyut iş parçaları için, ideal sayı, boyut kuralları ve saha düğmesinin 22 aralıkları tasarımı bakın. Uygulanan düğmeler 70 ° C&#39;de önceden ısıtılmış fırında yüz yukarı engelleme plakasını yerleştirin ºC. </li><li> Cilalı için değil iş parçasının yüzüne bandı uygulayın. Hava kabarcıkları üreten veya aşırı bant germe kaçının. </li><li> Fırında engelleme plakası üzerindeki düğmeler üzerine aşağı bant yan yüzü ile iş parçasını yerleştirin. Konvektif akışını en aza indirmek için parça-düğme-blok örtün. 1.5 saat sonra, oda sıcaklığına kadar 10 ° C / saat soğumaya fırın ayarlayın. Soğuduktan sonra, bloke iş parçası üzerinde zift kalınlığı ~ 1 mm olmalıdır. </li></ol> 3. Yakınsak Polisaj <ol><li> Parlatma sırasında kurumasını önlemek için bulamaç Cisr parlatıcı çevre odasındaki nem sistemi açın ve parçayı tırmalama haydut parçacıkları en aza indirmek için. </li><li> Insuzun boylu ve parlatıcı içine özel olarak tasarlanmış ve hazırlanmış septum monte edin. İş parçasını tutmak için Cisr parlatıcı ve alt bom içine PBB parçasını takın. </li><li> 75 mm ~ bir radyal inme ve 1 galon / dakika filtrasyon sistemi, bir harç akışı ile 25 rpm&#39;lik bir eşleştirilmiş tur ve iş parçasının bir dönme hızında 4 saat Cisr ile Polonya iş parçası. NOT: 0.6 psi basınç uygulanan iş parçası üzerinde yükleme ağırlığı ilgili olarak engelleme plakası da hizmet vermektedir. </li><li> Tur ve iş parçası dönme ve çamur akışını kapatın. Cisr parlatıcı gelen PBB parçasını çıkarın ve DI su dolu banyo içine batırın. Batık ise temiz oda bezle parça yüzeyini silin. DI su ile durulayın banyodan PBB parçasını çıkarın ve sprey. </li><li> İş parçası blok arayüzü bir dolgu takarak Deblock iş parçası. Malzeme yüzeyi bandı çıkarın. Agresif DI su ve kuru hava ile iş parçasını durulayın. </li><li> PBB Sonra po tekrar Bölüm 2&#39;de açıklandığı gibi iş parçasının karşıt yüzüBölüm 3&#39;te açıklanan prosedür Publishing. </li></ol> 4. Metroloji ve Denetim <ol><li> Ölçü bir interferometre ile iş parçasının her iki dalga cephesi (yani, yüzey şekil) ve aynı zamanda iletilen wavefront yansıtmaktadır. </li><li> Dağı parlak ışık muayene istasyonunda iş parçası ve optik fabrikasyon standart yöntemler kullanılarak çizik / kazı özelliklerini ölçmek. Aşama 2.1 &#39;de tarif edildiği gibi, iş parçasının bir kısa BOE aşındırma, yüksek akıcılık lazer uygulamalarında kullanılan iş parçaları için gizli çizikler ortaya çıkarmak için kullanılabilir. Iş parçası ince çizikler veya pürüzlülük ölçümü için standart optik mikroskopi ya da beyaz ışık interferometrisinin bir kullanılabilmektedir. </li><li> Mağaza parçasının yüzü olan bir kap minimize temas parçasını tamamladı. </li></ol>

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The authors have nothing to disclose.

Giriş bölümünde tartışıldığı gibi ortadan kaldırmak ya da bağlı parça şekline parça-kucak uyumsuzluğu dışında mekansal maddi olmayan tekdüzelik etkileyen tüm olayları en aza içerir, yakınsak başarılı bir şekilde uygulanması rakam yüzey ile ilgili Parlatma. Bu olayların herhangi bir uygun, ya proses kontrolü yoluyla veya parlatıcı, ardından istediğiniz yakınsama noktası elde veya muhafaza edilemez uygun mühendislik yoluyla azaltılabilir değilse; dolayısıyla aslında her azaltma...

Tipik bir optik üretim sürecinde önemli adımlar şekillendirme, taşlama, tam diyafram parlatma ve 1-3 parlatma bazen küçük bir araç içerir. Görüntüleme ve lazer sistemleri için yüksek kaliteli optik bileşenler için artan talebi ile, son birkaç yılda optik üretiminde önemli gelişmeler olmuştur. Örneğin, hassasiyet için, deterministik kazıma (CNC) cam şekillendirme makineleri Kontrollü Bilgisayar Sayısal gelişmeler ile şekillendirme ve öğütme işlemleri sırasında artık mümkün. Benzer şekilde, küçük bir araç parlatma teknolojileri (örneğin, bilgisayar kontrollü optik kaplama (CCOS), iyon endam, ve manyeto-reolojik terbiye (HÖH)) böylece güçlü optik imalat sektörü etkileyen, deterministik malzeme kaldırma ve yüzey şekil denetimi yol açmıştır. Ancak, terbiye süreci, tam diyafram parlatma ara adım, hala tipik yetenekli opticia gerektiren, yüksek determinizm yoksunns, birden yürütmek için genellikle birden fazla süreç değişiklikleri ile uzun, tekrarlı çevrim istenen yüzey şekil 1-3 ulaşmak için. parlatma yöntemleri, süreç değişkenleri ve karmaşık kimyasal ve iş parçası, kucak ve bulamaç 3-4 arasındaki mekanik etkileşimlerin çok sayıda zorlu bir bilim bir &#39;sanat&#39; optik parlatma dönüştürmeye yaptık. Deterministik tam diyafram parlatma elde etmek için, kazıma iyi anlaşılması gerekir. Tarihsel, kazıma yaygın olarak kullanılan Preston denklemi 5 tarafından tarif edilmiştir <img alt="Denklem 1" fo:content-width="1in" fo:src="/files/ftp_upload/51965/51965eqn1.jpg" src="/files/ftp_upload/51965/51965eqn1.jpg" width="100px" /> (1) dh / dt ortalama kalınlığı kaldırma oranı olduğu, k p Preston sabiti, σ o isimli birUygulanan basınç, ve V r iş parçası ve kucak arasındaki ortalama bağıl hızıdır. şematik mekansal ve zamansal hız varyasyonları ve basınç arasındaki farklar da dahil olmak üzere, Preston Denklemi açıklandığı gibi kazıma etkileyen fiziksel kavramları tasvir Şekil 1 uygulanan basınç ve basınç dağılımı parça deneyimleri ve sürtünme etkileri 6-8. Özel olarak, iş parçası ile yaşanan gerçek basınç dağılımının, büyük ölçüde, iş parçasının yüzeyi, şekil elde edilen etki (ayrıntılı olarak başka 6-8 tarif edilmiştir) fenomeni, bir dizi ile idare edilir. Ayrıca, Preston Eşitlik, mikroskobik ve moleküler düzeyde etkileri büyük ölçüde genel kazıma, mikro-pürüzleri ve hatta iş parçası üzerinde çizilmeye etkiler makroskopik Preston sabiti (k p), içine katlanır. Çeşitli çalışmalar hesap Preston modelini genişlettik<html> mikroskobik parçacık bulamaç-pad-iş parçası etkileşimleri kazıma ve microroughness 9-16 açıklamak için. Tam diyafram parlatma sırasında yüzey şeklin belirleyici kontrol elde etmek için, yukarıda tarif edilen olayların her biri anlaşılacaktır ölçülmesi ve daha sonra kontrol edilmesi gerekmektedir. Yakınsak Parlatma arkasındaki strateji ya mühendislik parlatıcı tasarımı sayesinde veya kaldırma nedeniyle parça şekline parça-kucak uyumsuzluğu sadece tahrik öyle ki süreç kontrolü ile, ortadan kaldırmak ya da düzgün olmayan malzeme çıkarılması istenmeyen nedenleri en aza indirmek için 7,17- 18. Şekil 2 parça şekil parça-kucak uyumsuzluğu kavramına dayalı yakınsama yol açabilir nasıl göstermektedir. Düz bir tur ve sol üst kısmında gösterilen karmaşık bir şekil varsayımsal iş parçasını düşünün. (boşluk, SH oL olarak anılacaktır) arayüzü yüksekliği uyuşmazlığı gibi arayüz basınç dağılımı (σ) etkiler: içeriği &quot;fo: keep-together.within sayfa =&quot; always &quot;&gt; <img alt="Denklem 2" fo:content-width="1in" fo:src="/files/ftp_upload/51965/51965eqn2.jpg" src="/files/ftp_upload/51965/51965eqn2.jpg" width="100px" /> (2) h sabit anlatan hızıdır hangi basınç farkı SH oL 6 artış ile azalır. Bu örnekte, iş parçası parlatma sırasında en yüksek ilk kazıma gözlemlemek olacaktır merkezinde en yüksek yerel basınç (Şekil 2 alt sol bakınız), ve dolayısıyla bu konuma sahiptir. Malzeme bertaraf gibi, iş parçası üzerindeki basınç farkı, çalışma parçası tur uyumsuzluğu bir azalmaya bağlı olarak azalır ve malzeme turun şekil yakınsar. Yakınsama, iş parçası basınç dağılımı ve dolayısıyla kazıma anda, (Şekil 2 sağ tarafını bakınız) iş parçası boyunca tek olacak. Bu örnek ancak buradan, düz bir tur için gösterilmiştirer, aynı kavram (içbükey veya dışbükey ya) bir küresel tur için geçerlidir. Mekansal malzeme olmayan tekdüzelik etkileyen tüm diğer fenomenler elimine edilmiş Yine, bu yakınsama süreci yalnızca çalışır. Yakınsak parlatılması protokolünde uygulanan spesifik prosedür ve mühendislik azaltıcı Tartışma tarif edilmiştir. Aşağıdaki çalışmada açıklanan protokol ince öğütülmüş yüzeyinden başlayarak 26.5 cm&#39;lik kare erimiş silis cam iş parçası için özel Yakınsak parlatma süreçtir. Parlatma 8 saat (4 saat / yüzey), bu iş parçası çok yüksek yüzey kalitesi (yani, düşük çizik yoğunluğu) ile ~ λ / 2 cilalı düzlük elde edebilirsiniz.

<table border="0" cellpadding="0" cellspacing="0" width="634">
	<tbody>
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			<td height="21" style="height:21px;width:251px;">Name of Material/Equipment</td>
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			<td>HASTILITE PO</td>
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			<td height="21" style="height:21px;">Diamond conditioner</td>
			<td>Morgan Advanced Ceramics&#160;</td>
			<td>CMP-25035-SFT</td>
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convergent polishing: a simple, rapid, full aperture polishing process of high quality optical flats &amp; spheres

Yakınsak Polisaj ilk şekli bağımsız bir iş parçası, (yani, yüzey şekil), bir sabit, değişmeyen kümesi altında mükemmel yüzey kalitesi ile son yüzey rakam yakınsama hangi düz ve küresel cam optik sonlandırma için yeni bir parlatma sistemi ve yöntemi olduğunu Tek bir parlatma tekrarında parametreleri parlatma. Buna karşılık, geleneksel tam diyafram parlatma yöntemleri, istenen yüzey rakam elde etmek için parlatma, metroloji ve süreç değişiklikleri içeren çoklu, genellikle uzun, iteratif döngüleri gerektirir. Yakınsak Polisaj işlemi kucağına şekline yakınsak parçada kaldırılması ve sonuçları ile azalır basınç farkı ile sonuçlanan iş parçası-kucak yüksekliği uyumsuzluğu kavramına dayanmaktadır. Yakınsak Polisaj işlemi başarılı bir şekilde uygulanması parça-kucak dışında düzgün olmayan mekansal malzeme kaldırma (bütün kaynaklarını çıkarmak için teknolojilerin bir dizi kombinasyonu bir sonucudurYüzey rakam yakınsama uyumsuzluğu) ve düşük yoğunlukları çizilmeye ve düşük pürüzlülük için sistemde kötü niyetli parçacıkların sayısını azaltmak için. Yakınsak Polisaj işlemi çeşitli cam malzemelerin hem daire ve çeşitli şekillerde, boyutlarda küreler, ve boy oranları imalatı için gösterilmiştir. Pratik etkisi yüksek kaliteli optik bileşenler alt birim maliyetleri sonuçlanan, daha az metroloji ile, ve daha az emek ile daha tekrar tekrar, daha hızlı imal edilebilir olmasıdır. Bu çalışmada, Yakınsak Cila protokolü özellikle kare bir 81 cm çapında parlatıcı yüzeye başına 4 saat parlatma sonra bir cilalı ~ λ / 2 yüzey şekil ince bir toprak yüzeyinden silika daireler kaynaşmış 26.5 cm imalatı için tarif edilmiştir.

Yakınsak parlatılması protokolü, yukarıda tarif edilen bir tepe girinti-çıkıntı düzlüğü, yüzey başına 4 saatlik tek bir yineleme, cilalı (bu durumda, bir 26.5 sm kare) bir zemin kaynaşık silika iş parçasını sağlar ~ λ / 2 (R düşük en-boy oranı, iş parçaları ve yüksek en-boy oranı, iş parçaları için ~ 1λ (~ 633 nm) için 330 nm) () bakınız Şekil 3. Yine, bu süreç tekrar tekrar parlatma parametrelerine değişiklik gerektirmeden aynı nihai yüzey rakam parçala...

Watch this Scientific Journal Video about Convergent Polishing: A Simple, Rapid, Full Aperture Polishing Process of High Quality Optical Flats & Spheres at JoVE.com

Convergent Polishing: A Simple, Rapid, Full Aperture Polishing Process of High Quality Optical Flats &amp; Spheres

A novel optical polishing process, called &#8220;Convergent Polishing&#8221;, which enables faster, lower cost polishing, is described. Unlike conventional polishing processes, Convergent Polishing allows a glass workpiece to be polished in a single iteration and with high surface quality to its final surface figure without requiring changes to polishing parameters.

Yakınsak Polisaj: Yüksek Kaliteli Optik Flats &amp; Kürelerin Basit, Hızlı, Tam Diyafram Parlatma İşlemi

Convergent Polishing is a novel polishing system and method for finishing flat and spherical glass optics in which a workpiece, independent of its initial ...

convergent-polishing-simple-rapid-full-aperture-polishing-process

Research

JoVE Journal

Engineering

11.0K Görüntüleme.  Lawrence Livermore National Laboratory. A novel optical polishing process, called “Convergent Polishing”, which enables faster, lower cost polishing, is described. Unlike conventional polishing processes, Convergent Polishing allows a glass workpiece to be polished in a single iteration and with high surface quality to its final surface figure without requiring changes to polishing parameters.

Video: Convergent Polishing: A Simple, Rapid, Full Aperture Polishing Process of High Quality Optical Flats & Spheres

Fabrication of Silica Ultra High Quality Factor Microresonators

Whispering gallery resonant cavities confine light in circular orbits at their periphery.1-2 The photon storage lifetime in the cavity, quantified by the quality factor (Q) of the cavity, can be in excess of 500ns for cavities with Q factors above 100 million. As a result of their low material losses, silica microcavities have demonstrated some of the longest photon lifetimes to date1-2. Since a portion of the circulating light extends outside the resonator, these devices can also be used to probe the surroundings. This interaction has enabled numerous experiments in biology, such as single molecule biodetection and antibody-antigen kinetics, as well as discoveries in other fields, such as development of ultra-low-threshold microlasers, characterization of thin films, and cavity quantum electrodynamics studies.3-7
The two primary silica resonant cavity geometries are the microsphere and the microtoroid. Both devices rely on a carbon dioxide laser reflow step to achieve their ultra-high-Q factors (Q&gt;100 million).1-2,8-9 However, there are several notable differences between the two structures. Silica microspheres are free-standing, supported by a single optical fiber, whereas silica microtoroids can be fabricated on a silicon wafer in large arrays using a combination of lithography and etching steps. These differences influence which device is optimal for a given experiment.
Here, we present detailed fabrication protocols for both types of resonant cavities. While the fabrication of microsphere resonant cavities is fairly straightforward, the fabrication of microtoroid resonant cavities requires additional specialized equipment and facilities (cleanroom). Therefore, this additional requirement may also influence which device is selected for a given experiment.
Introduction
An optical resonator efficiently confines light at specific wavelengths, known as the resonant wavelengths of the device. 1-2 The common figure of merit for these optical resonators is the quality factor or Q. This term describes the photon lifetime (&tau;o) within the resonator, which is directly related to the resonator's optical losses. Therefore, an optical resonator with a high Q factor has low optical losses, long photon lifetimes, and very low photon decay rates (1/&tau;o). As a result of the long photon lifetimes, it is possible to build-up extremely large circulating optical field intensities in these devices. This very unique property has allowed these devices to be used as laser sources and integrated biosensors.10
A unique sub-class of resonators is the whispering gallery mode optical microcavity. In these devices, the light is confined in circular orbits at the periphery. Therefore, the field is not completely confined within the device, but evanesces into the environment. Whispering gallery mode optical cavities have demonstrated some of the highest quality factors of any optical resonant cavity to date.9,11 Therefore, these devices are used throughout science and engineering, including in fundamental physics studies and in telecommunications as well as in biodetection experiments. 3-7,12
Optical microcavities can be fabricated from a wide range of materials and in a wide variety of geometries. A few examples include silica and silicon microtoroids, silicon, silicon nitride, and silica microdisks, micropillars, and silica and polymer microrings.13-17 The range in quality factor (Q) varies as dramatically as the geometry. Although both geometry and high Q are important considerations in any field, in many applications, there is far greater leverage in boosting device performance through Q enhancement. Among the numerous options detailed previously, the silica microsphere and the silica microtoroid resonator have achieved some of the highest Q factors to date.1,9 Additionally, as a result of the extremely low optical loss of silica from the visible through the near-IR, both microspheres and microtoroids are able to maintain their Q factors over a wide range of testing wavelengths.18 Finally, because silica is inherently biocompatible, it is routinely used in biodetection experiments.
In addition to high material absorption, there are several other potential loss mechanisms, including surface roughness, radiation loss, and contamination loss.2 Through an optimization of the device size, it is possible to eliminate radiation losses, which arise from poor optical field confinement within the device. Similarly, by storing a device in an appropriately clean environment, contamination of the surface can be minimized. Therefore, in addition to material loss, surface scattering is the primary loss mechanism of concern.2,8
In silica devices, surface scattering is minimized by using a laser reflow technique, which melts the silica through surface tension induced reflow. While spherical optical resonators have been studied for many years, it is only with recent advances in fabrication technologies that researchers been able to fabricate high quality silica optical toroidal microresonators (Q&gt;100 million) on a silicon substrate, thus paving the way for integration with microfluidics.1
The present series of protocols details how to fabricate both silica microsphere and microtoroid resonant cavities. While silica microsphere resonant cavities are well-established, microtoroid resonant cavities were only recently invented.1 As many of the fundamental methods used to fabricate the microsphere are also used in the more complex microtoroid fabrication procedure, by including both in a single protocol it will enable researchers to more easily trouble-shoot their experiments.

We describe the use of a carbon dioxide laser reflow technique to fabricate silica resonant cavities, including free-standing microspheres and on-chip microtoroids. The reflow method removes surface imperfections, allowing long photon lifetimes within both devices. The resulting devices have ultra high quality factors, enabling applications ranging from telecommunications to biodetection.

Silika Ultra Yüksek Kalite Faktörü Microresonators Fabrikasyon

Whispering gallery resonant cavities confine light in circular orbits at their periphery.1-2 The photon storage lifetime in the cavity, quantified by the ...

Mühendislik

Process of Making Three-dimensional Microstructures using Vaporization of a Sacrificial Component

Vascular structures in natural systems are able to provide high mass transport through high surface areas and optimized structure. Few synthetic material fabrication techniques are able to mimic the complexity of these structures while maintaining scalability. The Vaporization of a Sacrificial Component (VaSC) process is able to do so. This process uses sacrificial fibers as a template to form hollow, cylindrical microchannels embedded within a matrix. Tin (II) oxalate (SnOx) is embedded within poly(lactic) acid (PLA) fibers which facilitates the use of this process. The SnOx catalyzes the depolymerization of the PLA fibers at lower temperatures. The lactic acid monomers are gaseous at these temperatures and can be removed from the embedded matrix at temperatures that do not damage the matrix. Here we show a method for aligning these fibers using micromachined plates and a tensioning device to create complex patterns of three-dimensionally arrayed microchannels. The process allows the exploration of virtually any arrangement of fiber topologies and structures.

The Vaporization of a Sacrificial Component (VaSC) process is used to fabricate microvascular structures. This procedure uses sacrificial poly(lactic) acid fibers to form hollow microchannels with precise 3D geometric positioning provided by laser micromachined guide plates.

Bir Kurban bileşeni buharlaşma kullanarak üç boyutlu Mikroyapılar Yapma Süreci

Vascular structures in natural systems are able to provide high mass transport through high surface areas and optimized structure. Few synthetic material ...

Construction of a High Resolution Microscope with Conventional and Holographic Optical Trapping Capabilities

High resolution microscope systems with optical traps allow for precise manipulation of various refractive objects, such as dielectric beads 1 or cellular organelles 2,3, as well as for high spatial and temporal resolution readout of their position relative to the center of the trap. The system described herein has one such "traditional" trap operating at 980 nm. It additionally provides a second optical trapping system that uses a commercially available holographic package to simultaneously create and manipulate complex trapping patterns in the field of view of the microscope 4,5 at a wavelength of 1,064 nm. The combination of the two systems allows for the manipulation of multiple refractive objects at the same time while simultaneously conducting high speed and high resolution measurements of motion and force production at nanometer and piconewton scale.

The system described herein employs a traditional optical trap as well as an independent holographic optical trapping line, capable of creating and manipulating multiple traps. This allows for the creation of complex geometric arrangements of refractive particles while also permitting simultaneous high-speed, high-resolution measurements of the activity of biological enzymes.

Geleneksel ve Holografik Optik Yakalama Yetenekleri ile bir Yüksek Çözünürlüklü Mikroskop İnşaatı

High resolution microscope systems with optical traps allow for precise manipulation of various refractive objects, such as dielectric beads 1 or cellular ...

The Generation of Higher-order Laguerre-Gauss Optical Beams for High-precision Interferometry

Thermal noise in high-reflectivity mirrors is a major impediment for several types of high-precision interferometric experiments that aim to reach the standard quantum limit or to cool mechanical systems to their quantum ground state. This is for example the case of future gravitational wave observatories, whose sensitivity to gravitational wave signals is expected to be limited in the most sensitive frequency band, by atomic vibration of their mirror masses. One promising approach being pursued to overcome this limitation is to employ higher-order Laguerre-Gauss (LG) optical beams in place of the conventionally used fundamental mode. Owing to their more homogeneous light intensity distribution these beams average more effectively over the thermally driven fluctuations of the mirror surface, which in turn reduces the uncertainty in the mirror position sensed by the laser light.
We demonstrate a promising method to generate higher-order LG beams by shaping a fundamental Gaussian beam with the help of diffractive optical elements. We show that with conventional sensing and control techniques that are known for stabilizing fundamental laser beams, higher-order LG modes can be purified and stabilized just as well at a comparably high level. A set of diagnostic tools allows us to control and tailor the properties of generated LG beams. This enabled us to produce an LG beam with the highest purity reported to date. The demonstrated compatibility of higher-order LG modes with standard interferometry techniques and with the use of standard spherical optics makes them an ideal candidate for application in a future generation of high-precision interferometry.

Large laser-interferometers are being constructed to create a new type of astronomy based on gravitational waves. Their sensitivities, as for many other high-precision experiments, are approaching fundamental noise limits such as the atomic vibration of their components. We are pioneering technologies to overcome these limits using novel laser beam shapes.

Yüksek hassasiyetli İnterferometre için Yüksek mertebeden Laguerre-Gauss Optik Kirişlerin Üretimi

Thermal noise in high-reflectivity mirrors is a major impediment for several  types of high-precision interferometric experiments that aim to reach the  ...

Fabrication Process of Silicone-based Dielectric Elastomer Actuators

This contribution demonstrates the fabrication process of dielectric elastomer transducers (DETs). DETs are stretchable capacitors consisting of an elastomeric dielectric membrane sandwiched between two compliant electrodes. The large actuation strains of these transducers when used as actuators (over 300% area strain) and their soft and compliant nature has been exploited for a wide range of applications, including electrically tunable optics, haptic feedback devices, wave-energy harvesting, deformable cell-culture devices, compliant grippers, and propulsion of a bio-inspired fish-like airship. In most cases, DETs are made with a commercial proprietary acrylic elastomer and with hand-applied electrodes of carbon powder or carbon grease. This combination leads to non-reproducible and slow actuators exhibiting viscoelastic creep and a short lifetime. We present here a complete process flow for the reproducible fabrication of DETs based on thin elastomeric silicone films, including casting of thin silicone membranes, membrane release and prestretching, patterning of robust compliant electrodes, assembly and testing. The membranes are cast on flexible polyethylene terephthalate (PET) substrates coated with a water-soluble sacrificial layer for ease of release. The electrodes consist of carbon black particles dispersed into a silicone matrix and patterned using a stamping technique, which leads to precisely-defined compliant electrodes that present a high adhesion to the dielectric membrane on which they are applied.

This manuscript shows the fabrication process for the manufacture of dielectric elastomer soft actuators based on silicone membranes. The three key stages of production are presented in detail: blade casting of thin silicone membranes; pad printing of compliant electrodes; and the assembly of all the components.

Silikon tabanlı Dielektrik Elastomer Aktüatörler Fabrikasyon Süreci

This contribution demonstrates the fabrication process of dielectric elastomer transducers (DETs). DETs are stretchable capacitors consisting of an ...

Adsorption Device Based on a Langatate Crystal Microbalance for High Temperature High Pressure Gas Adsorption in Zeolite H-ZSM-5

We present a high-temperature and high-pressure gas adsorption measurement device based on a high-frequency oscillating microbalance (5 MHz langatate crystal microbalance, LCM) and its use for gas adsorption measurements in zeolite H-ZSM-5. Prior to the adsorption measurements, zeolite H-ZSM-5 crystals were synthesized on the gold electrode in the center of the LCM, without covering the connection points of the gold electrodes to the oscillator, by the steam-assisted crystallization (SAC) method, so that the zeolite crystals remain attached to the oscillating microbalance while keeping good electroconductivity of the LCM during the adsorption measurements. Compared to a conventional quartz crystal microbalance (QCM) which is limited to temperatures below 80 &#176;C, the LCM can realize the adsorption measurements in principle at temperatures as high as 200-300 &#176;C (i.e., at or close to the reaction temperature of the target application of one-stage DME synthesis from the synthesis gas), owing to the absence of crystalline-phase transitions up to its melting point (1,470 &#176;C). The system was applied to investigate the adsorption of CO2, H2O, methanol and dimethyl ether (DME), each in the gas phase, on zeolite H-ZSM-5 in the temperature and pressure range of 50-150 &#176;C and 0-18 bar, respectively. The results showed that the adsorption isotherms of these gases in H-ZSM-5 can be well fitted by Langmuir-type adsorption isotherms. Furthermore, the determined adsorption parameters, i.e., adsorption capacities, adsorption enthalpies, and adsorption entropies, compare well to literature data. In this work, the results for CO2 are shown as an example.

A protocol for high-temperature and high-pressure gas adsorption measurements on zeolite H-ZSM-5 using an adsorption measurement device based on a langatate crystal microbalance is presented. Prior to the adsorption measurements, the synthesis of zeolite H-ZSM-5 on the langatate crystal microbalance sensor by the steam-assisted crystallization (SAC) method is demonstrated.

Zeolit ​​Yüksek Sıcaklık Yüksek Basınçlı Gaz Adsorpsiyon için Langatate kristal mikro dayanarak Adsorpsiyon Cihazı H-ZSM-5

We present a high-temperature and high-pressure gas adsorption measurement device based on a high-frequency oscillating microbalance (5 MHz langatate ...

Challenges in Rheological Characterization of Highly Concentrated Suspensions &#8212; A Case Study for Screen-printing Silver Pastes

A comprehensive rheological characterization of highly concentrated suspensions or pastes is mandatory for a targeted product development meeting the manifold requirements during processing and application of such complex fluids. In this investigation, measuring protocols for a conclusive assessment of different process relevant rheological parameters have been evaluated. This includes the determination of yield stress, viscosity, wall slip velocity, structural recovery after large deformation and elongation at break as well as tensile force during filament stretching.
The importance of concomitant video recordings during parallel-plate rotational rheometry for a significant determination of rheological quantities is demonstrated. The deformation profile and flow field at the sample edge can be determined using appropriate markers. Thus, measurement parameter settings and plate roughness values can be identified for which yield stress and viscosity measurements are possible. Slip velocity can be measured directly and measuring conditions at which plug flow, shear banding or sample spillover occur can be identified clearly. 
Video recordings further confirm that the change in shear moduli observed during three stage oscillatory shear tests with small deformation amplitude in stage I and III but large oscillation amplitude in stage II can be directly attributed to structural break down and recovery. For the pastes investigated here, the degree of irreversible, shear-induced structural change increases with increasing deformation amplitude in stage II until a saturation is reached at deformations corresponding to the crossover of G' and G'', but the irreversible damage is independent of the duration of large amplitude shear. 
A capillary breakup elongational rheometer and a tensile tester have been used to characterize deformation and breakup behavior of highly filled pastes in uniaxial elongation. Significant differences were observed in all experiments described above for two commercial screen-printing silver pastes used for front side metallization of Si-solar cells.

Challenges in Rheological Characterization of Highly Concentrated Suspensions &amp;#8212; A Case Study for Screen-printing Silver Pastes

A protocol for a robust and application relevant rheological characterization of highly concentrated suspensions is presented. Silver pastes used for screen-printing application in solar cell production are employed as model systems.

Son derece Konsantre Süspansiyonlarının reolojik Karakterizasyonunda Zorluklar - Ekran-baskı Gümüş Pastaları için bir Vaka Çalışması

A comprehensive rheological characterization of highly concentrated suspensions or pastes is mandatory for a targeted product development meeting the ...

Method for Recording Broadband High Resolution Emission Spectra of Laboratory Lightning Arcs

Lightning is one of the most common and destructive forces in nature and has long been studied using spectroscopic techniques, first with traditional camera film methods and then digital camera technology, from which several important characteristics have been derived. However, such work has always been limited due to the inherently random and non-repeatable nature of natural lightning events in the field. Recent developments in lightning test facilities now allow the reproducible generation of lightning arcs within controlled laboratory environments, providing a test bed for the development of new sensors and diagnostic techniques to understand lightning mechanisms better. One such technique is a spectroscopic system using digital camera technology capable of identifying the chemical elements with which the lightning arc interacts, with these data then being used to derive further characteristics. In this paper, the spectroscopic system is used to obtain the emission spectrum from a 100 kA peak, 100 &#181;s duration lightning arc generated across a pair of hemispherical tungsten electrodes separated by a small air gap. To maintain a spectral resolution of less than 1 nm, several individual spectra were recorded across discrete wavelength ranges, averaged, stitched, and corrected to produce a final composite spectrum in the 450 nm (blue light) to 890 nm (near infrared light) range. Characteristic peaks within the data were then compared to an established publicly available database to identify the chemical element interactions. This method is readily applicable to a variety of other light emitting events, such as fast electrical discharges, partial discharges, and sparking in electrical equipment, apparatus, and systems.

Emission spectroscopy techniques have traditionally been used to analyze inherently random lightning arcs occurring in nature. In this paper, a method developed to obtain the emission spectroscopy from reproducible lightning arcs generated within a laboratory environment is described.

Laboratuvar Yıldırım Yaylar Genişbant Yüksek Çözünürlüklü Emisyon Spectra Kayıt Yöntemi

Lightning is one of the most common and destructive forces in nature and has long been studied using spectroscopic techniques, first with traditional ...

Atomic Layer Deposition of Vanadium Dioxide and a Temperature-dependent Optical Model

Vanadium dioxide is a material that has a reversible metal-insulator phase change near 68 &#176;C. To grow VO2 on a wide variety of substrates, with wafer-scale uniformity and angstrom level control of thickness, the method of atomic-layer deposition was chosen. This ALD process enables high-quality, low-temperature (&#8804;150 &#176;C) growth of ultrathin films (100-1000 &#197;) of VO2. For this demonstration, the VO2 films were grown on sapphire substrates. This low temperature growth technique produces mostly amorphous VO2 films. A subsequent anneal in an ultra-high vacuum chamber with a pressure of 7x10-4 Pa of ultra-high purity (99.999%) oxygen produced oriented, polycrystalline VO2 films. The crystallinity, phase, and strain of the VO2 were determined by Raman spectroscopy and X-ray diffraction, while the stoichiometry and impurity levels were determined by X-ray photoelectron spectroscopy, and finally the morphology was determined by atomic force microscopy. These data demonstrate the high-quality of the films grown by this technique. A model was created to fit to the data for VO2 in its metallic and insulating phases in the near infrared spectral region. The permittivity and refractive index of the ALD VO2 agreed well with the other fabrication methods in its insulating phase, but showed a difference in its metallic state. Finally, the analysis of the films&#39; optical properties enabled the creation of a wavelength- and temperature-dependent model of the complex optical refractive index for developing VO2 as a tunable refractive index material.

Thin films (100-1000 &#197;) of vanadium dioxide (VO2) were created by atomic-layer deposition (ALD) on sapphire substrates. Following this, the optical properties were characterized through the metal-insulator transition of VO2. From the measured optical properties, a model was created to describe the tunable refractive index of VO2.

Atom katman birikimi Vanadyum dioksit ve sıcaklık-bağımlı optik manken

Vanadium dioxide is a material that has a reversible metal-insulator phase change near 68 &#176;C. To grow VO2 on a wide variety of substrates, with ...

Predicting Catalyst Extrudate Breakage Based on the Modulus of Rupture

The mechanical strength of extruded catalysts and their natural or forced breakage by either collision against a surface or by a compressive load in a fixed bed are important phenomena in catalyst technology. The mechanical strength of the catalyst is measured here by its bending strength or flexural strength. This technique is relatively new from the perspective of applying it to commercial catalysts of typical sizes used in the industry. Catalyst breakage by collision against a surface is measured after a fall of the extrudates through the ambient air in a vertical pipe. Quantifying the impact force is done theoretically by applying Newton's second law. Measurement of catalyst breakage due to stress in a fixed bed is done following the standard procedure of the bulk crush strength test. Novel here is the focus on measuring the reduction in the length to diameter ratio of the extrudates as a function of the stress.

Here we present a protocol to measure the modulus of rupture of an extruded catalyst and the breakage of said catalyst extrudates by collision against a surface or by compression in a fixed bed.

Predicting katalizör Extrudate kırılma rüptürü modülü üzerinde dayalı

The mechanical strength of extruded catalysts and their natural or forced breakage by either collision against a surface or by a compressive load in a ...