Name: a performance-testing platform for a conduction micropump with an fr-4 copper-clad electrode plate
Uploaded: 2017-10-09T13:00:00.000+00:00
Duration: 6 min 46 s
Description: Watch this Scientific Journal Video about A Performance-testing Platform for a Conduction Micropump with an FR-4 Copper-clad Electrode Plate at JoVE.com

Bu eser Ulusal Doğa Bilimleri Vakfı Çin tarafından (51375176); sponsor oldu Guangdong İl doğal Bilim Vakfı Çin (2014A030313264); ve bilim ve teknoloji proje Guangdong Eyaleti, Çin (2014B010126003) planlama.

dikkat: ilgili tüm malzeme güvenlik bilgi formları (MSDS) kullanmadan önce lütfen danışın. Aseton son derece yanıcı ve gözleri ve solunum yolu tahrişe neden olabilir. Gerilim ilgili birkaç bin volt olarak yüksektir; Bu nedenle, elektrik sparks deney zaman bekleniyor. Kıvılcım yangın ve patlamalar önlemek için iyi bir havalandırma ile bir odada deneyler yürütmek.
 1. tabakalar ve tutucu imalatı Not: Bu çalışmada, bir fabrikada bir üretim hattiyla genisletildi cihazlarında elektrot tabakalar ve tutucu. Sadece malzeme ve bu kağıt her yerinde parametreler nedeniyle karmaşık süreçler tanıtılacaktır.
<ol><li>Malzeme ve elektrot plaka boyutunu <ol><li>Fabricate elektrot plakaları 1.4 mm kullanarak FR-4 CCL 35 µm ince bakır tabakası ile. Elektrot plaka detaylı parametreleri için bkz: şekil 1.</li>
	</ol></li> <li>Parametreleri elektrot <ol><li>elektrot plakaları fabrikadan sipariş. Daha fazla bilgi için bkz: Şekil 2.</li>
	</ol></li> <li>Elektrot plaka incelenmesi <ol><li>elektrot plaka hazırlanması sonra bir elektron mikroskobu altında 100 X ve 300 X büyütme göze çarpan herhangi bir kusurları için elektrotlar incelemek için kullanın. şekil 3 ' te gösterilen elektrot yüzeyinde herhangi bir küçük kusurları kısa devre, neden olabileceğini unutmayın.</li>
		<li>Kontrol ve elektrot genişlik ve Aralık boyut doğruluk gereksinimi uygun olup olmadığını belirlemek için ölçmek.</li>
		<li>Bir elektrik short-circuit oluşup oluşmayacağını görmek üzere bir amperemeter ile plaka testi.</li>
	</ol></li> <li>Hazırlık odası plaka <ol><li>bazı silikon membran elektrot plaka ile aynı boyutta için şekil 4 ' te gösterildiği gibi kesti. Silikon membranlar ile farklı yükseklikte pilakalar odası yapmak için farklı kalınlıklarda seçin.</li>
		<li>Özel bir Delme araç odası delik için şekil 5 ' te gösterildiği gibi kullanın.</li>
	</ol></li> <li>Sahibi işleme <ol><li>bir fabrika sahibinden sipariş. Detaylı parametreleri şekil 6 ' da gösterilen.</li>
	</ol></li> <li>Kapak plakasını imalatı <ol><li>üst kısmında bir sondaj kullanarak kapak plakasını matkap iki delik makine giriş ve çıkış boruları yüklemek için. Kendi pozisyonları ve boyutları için Şekil 7 bkz.</li>
	</ol></li></ol> 2. Micropump Meclisi <ol><li>yıkama için tüm plakaları, sahibi, giriş ve çıkış boruları ve deneylerde kullanılan diğer araçları kullanım aseton. Bu araçlar ve plakaları bir ölçek içinde koymak ve sonra onları sokmak için yeterli % 99.5 aseton dökün. İçinde ultrasonik yıkama kabı koymak. Ultrasonik yıkama açmak ve 5 dk. fırının saatini kurdu</li>
	<li>İki delik kapak plaka üzerinde giriş ve çıkış paslanmaz çelik tüpler takın.</li>
	<li>Silikon membran elektrot plaka üzerinde yapılmış bir odası tabak yerleştirin ve sonra kapak plakasını ile kapağı.</li>
	<li>Yığını ve kapak plakasını hizalamak, Oda plaka ve elektrot plaka yukarıdan aşağıya doğru ve hizalanmış plakaları tutucusuna takın.
	<ol><li>Kullanımı bir M5 cıvata plaka sahibi içinde düzeltmek için. Patlama görünümü ve monte micropump, normal görünüm şekil 8 ve 9 şekil, sırasıyla gösterildiği bkz.</li>
		<li>Basın plakaları birlikte civata sıkma. 
		Not: Tüpler ve Oda plaka den bir geçiş için çalışma sıvı oluşturacak. Elastik odası plaka da dışarı akan sıvı önlemek için plakalar arasındaki boşluğu kapatın. Patlama ve monte micropump şekil 8 ve 9 şekil, normal görünümünde sırasıyla bkz.</li>
	</ol></li> <li>İki poliüretan hortumlar 4 mm dış çap ve 2 mm iç çapı ile giriş ve çıkış paslanmaz çelik tüpler bağlamak için kullanın.</li>
	<li>Bir amperemeter, bir 500 V DC güç kaynağı ve micropump dizi bağlayın. 1 eklemek mA sigorta amperemeter ve micropump kısa devre durumunda amperemeter korumak için güç kaynağı arasında.</li>
	<li>50 mL kabı ile 20-30 mL aseton içinde içine giriş hortumu takın. 
	Not: Şekil 10 tamamlanan platform gösterir.</li>
</ol> 3. Deneysel bir işlem <ol><li>hazırlık deneme önce işe <ol><li>'ni bir silindir micropump kadar doldurmak için aseton enjekte etmek. Sıvı düzey çıkış hortumu ulaştıktan sonra tüm kabarcıklar uzak odası itilir kadar aseton içinde 10 mL enjekte etmek devam. 
		Not: Bu kapak plakasını ve elektrot plaka şeffaf olmadığı için oda içinde yaptı herhangi bir kabarcık olup olmadığını görmek mümkün değildir. Sürekli aseton enjekte kabarcıklar giderilmesine yardımcı olur, ancak hava kabarcığı yok micropump içinde bırakılır garanti edemeyiz. Kabarcıklar sıvı geçişini engelleyebilir veya kısa devreler ve elektrotlar yanacak micropump içinde bir mikro-patlamaya neden olabilir. Kabarcıklar etkisi pompa işlemi tamamen açık henüz değil, ama onlar neden arıza birkaç kez gözlenmiştir.</li>
		<li>20-30 mL aseton kabı dökün ve giriş hortum kabı koymak. Böylece aseton pompa akışı ve hava micropump odanın içine sucked sıvı düzeyi en az 5 mm giriş yüksek olduğundan emin olun.</li>
	</ol></li> <li>Statik basınç test <ol><li>hortumu düz ve dikey kalabileceği çıkış hortumu küçük bir kareye ekleyin. Sıvı düzeyini ölçmek için cetvel çıkış hortumu yanında koydu.</li>
		<li>Micropump güç kaynağına bağlayın.</li>
		<li>Test düğmeye basarak başlatın ve ardından başlangıç sıvı düzeyi işaretleyecektir.</li>
		<li>Sıvı seviyesi kararlı olduktan sonra zaman, son sıvı seviyesi ve elektrik akımı kaydetmek.</li>
		<li>Sıvı düzeyi ve geçerli her 10 kaydetmek devam micropump tatili kadar s.</li>
	</ol></li> <li>Akış hızı test <ol><li>büyük bir ölçüm silindir çıkış hortumdan gelen sıvı toplamak için kullanın. Böylece sonunda ölçek sıvı düzeyi olarak aynı yükseklikte kalır çıkış hortumu düzeltmek emin olun.</li>
		<li>Micropump güç kaynağına bağlayın.</li>
		<li>Test düğmeye basarak başlatın ve ardından başlangıç sıvı düzeyi işaretleyecektir.</li>
		<li>Sıvı çıkış hortumdan akmaya başladığında kayıt aseton içinde ölçüm silindir hacmi her 10 s. Deneme ilerledikçe, Sıvı düzey korumak için kabı aseton ekleyin.</li>
	</ol></li> <li>Güvenilirlik test
	<ol>Pompa güvenilirliğini değerlendirmek için <li>kullanımı ortalama çalışma zamanı. Akış oranı test ve statik basınç testi sırasında pompa çalışmaz hale önce operasyon süresi kaydedin. Deneme sırasında her arıza ayrıntılı olayları kaydetmek ve daha sonra daha ayrıntılı bir çözümleme için elektrot plaka yüzey incelemek.</li>
	</ol>
	</li>
</ol>

<ol>
	<li>Kazemi, P. Z., Selvaganapathy, P. R., Ching, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+micropillar+electrode+spacing+on+the+performance+of+electrohydrodynamic+micropumps.">Effect of micropillar electrode spacing on the performance of electrohydrodynamic micropumps.</a> J Electrostat. 68 (4), 376-383 (2010).</li><li>Kano, I., Nishina, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+electrode+arrangements+on+EHD+conduction+pumping.">Effect of electrode arrangements on EHD conduction pumping.</a> IEEE Trans Ind Appl. 49 (2), 679-684 (2013).</li><li>Laser, D. J., Santiago, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+review+of+micropumps.">A review of micropumps.</a> J Micromech Microeng. 14 (6), R35 (2004).</li><li>Fylladitakis, E. D., Theodoridis, M. P., Moronis, A. X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Review+on+the+history,+research,+and+applications+of+electrohydrodynamics.">Review on the history, research, and applications of electrohydrodynamics.</a> IEEE Trans Plasma Sci. 42 (2), 358-375 (2014).</li><li>Yazdani, M., Seyed-Yagoobi, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Electrostatics Joint Conf. , (2009).</li><li>Gharraei, R., Esmaeilzadeh, E., Hemayatkhah, M., Danaeefar, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+investigation+of+electrohydrodynamic+conduction+pumping+of+various+liquids+film+using+flush+electrodes.">Experimental investigation of electrohydrodynamic conduction pumping of various liquids film using flush electrodes.</a> J Electrostat. 69 (1), 43-53 (2011).</li><li>Gharraei, R., Esmaeilzadeh, E., Nobari, M. R. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Numerical+investigation+of+conduction+pumping+of+dielectric+liquid+film+using+flush-mounted+electrodes.">Numerical investigation of conduction pumping of dielectric liquid film using flush-mounted electrodes.</a> Theor Comp Fluid Dyn. 28 (1), 89 (2014).</li><li>Jeong, S. -. I., Seyed-Yagoobi, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+study+of+electrohydrodynamic+pumping+through+conduction+phenomenon.">Experimental study of electrohydrodynamic pumping through conduction phenomenon.</a> J Electrostat. 56 (2), 123-133 (2002).</li><li>Seyed-Yagoobi, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrohydrodynamic+pumping+of+dielectric+liquids.">Electrohydrodynamic pumping of dielectric liquids.</a> J Electrostat. 63 (6), 861-869 (2005).</li><li>Hojjati, M., Esmaeilzadeh, E., Sadri, B., Gharraei, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrohydrodynamic+conduction+pumps+with+cylindrical+electrodes+for+pumping+of+dielectric+liquid+film+in+an+open+channel.">Electrohydrodynamic conduction pumps with cylindrical electrodes for pumping of dielectric liquid film in an open channel.</a> Colloid Surface A. 392 (1), 294-299 (2011).</li><li>Yazdani, M., Seyed-Yagoobi, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Numerical+investigation+of+electrohydrodynamic-conduction+pumping+of+liquid+film+in+the+presence+of+evaporation.">Numerical investigation of electrohydrodynamic-conduction pumping of liquid film in the presence of evaporation.</a> J Heat Trans-T ASME. 131 (1), 011602 (2009).</li><li>Vafaie, R. H., Ghavifekr, H. B., Lintel, H., Brugger, J., Renaud, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bi-directional+AC+electrothermal+micropump+for+on-chip+biological+applications.">Bi-directional AC electrothermal micropump for on-chip biological applications.</a> Electrophoresis. 37 (5-6), 719-726 (2016).</li><li>Pearson, M. R., Seyed-Yagoobi, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+Study+of+Linear+and+Radial+Two-Phase+Heat+Transport+Devices+Driven+by+Electrohydrodynamic+Conduction+Pumping.">Experimental Study of Linear and Radial Two-Phase Heat Transport Devices Driven by Electrohydrodynamic Conduction Pumping.</a> J Heat Trans-T ASME. 137 (2), 022901 (2015).</li></ol>

Yazarlar ifşa gerek yok.

Protokol içindeki kritik adımlar elektrot plaka dikkatle incelemek için biridir. Bir elektrot kenarına küçük kenar pürüzleri içinde bir short-circuit neden olabilir ve yüzey bütünlük pompa performansını büyük oranda etkileyebilir. Elektrot plaka ve tutucu temizliği de çok önemlidir. Bu yüzden küçük toz parçacıklarının çalışma sıvı akışını bloke edebilir ve bir short-circuit neden elektrot Odası 1 mm'den az yüksekliğidir. Önce test, aseton odanın içine enjekte kabarcıklar odas?...

Micropumps sıvı akışı çok daha küçük bir ölçekte en pompaları daha sürebilir. Son yıllarda, çeşitli sürüş programları mikrosıvısal sistemleri1,2,3,4,5' e başarıyla uygulandı. Electrohydrodynamic (EHD) pompa Kuvvetleri hangi geçici o basit ve kolay6imal etmek doğrudan sıvı üzerinde herhangi bir hareketli parçalar olmadan uygulamayın. Şarj türlerine göre EHD pompa enjeksiyon pompaları, indüksiyon pompaları veya iletim pompalar sınıflandırılabilir. Enjeksiyon pompaları Sıvı iletkenlik değiştirmek ise indüksiyon Pompalar, izotermal sıvılar üzerinde çalışmaz. Onlar böyle bir sorun eksikliği nedeniyle iletim pompalar daha istikrarlı ve daha geniş bir uygulama var.
İletim pompanın sıvı molekülleri ayrılma ve rekombinasyon oranları uyuşmazlığı üzerinde temel alır. Normalde, ayrışma ve rekombinasyon işleminin7,8aşağıdaki gibi ifade edilebilir: 
<img alt="Equation" src="/files/ftp_upload/55867/55867eq1.jpg"> ayrılma oranı kd elektrik alan şiddeti bir fonksiyonu ise sürekli rekombinasyon oranı kr nerede. Elektrik alan şiddeti belirli bir değere ulaştığında, ayrılma oranı rekombinasyon hızı aşıyor. O zaman, daha fazla ücretsiz ücretleri Ters polarite ve heterocharge Katmanlar formu iki elektrot için seyahat. Masraf hareketinin sıvı molekülleri ileri iter gibi bu heterocharge Katmanlar pompa, anahtarıdır. Bu nedenle, net vücut kuvvet kullanarak asimetrik elektrotlar veya pozitif ve negatif iyonlar9,10,11,12 hareketliliğini uyuşmazlığı odası içinde sıvı oluşturulabilir .
Bu eser bir simetrik düzlemsel elektrot tabak ve tel pompa imalatı, yeni bir yol sunar. Elektrot plaka üzerinde FR-4 CCL hazırlanır ve Pompa Odası mikro işleme tarafından hazırlanmıştır. İmalat işlemleri nispeten daha basit ve daha nanolithography gibi diğer üretim yöntemlerini daha uygun. Test platformu farklı koşullar altında ve tel micropump performansını araştırmak için ayarlanır. Ayrıca, ve tel micropump güvenilirliğini de farklı koşullarda araştırıldı.

<table><tbody><tr><td>Amperemeter</td><td>-</td><td>85C1-MA</td><td></td></tr><tr><td>DC high voltage power supply</td><td>NanTong Jianuo electric device company</td><td>GY-WY500-1</td><td></td></tr><tr><td>Fuse</td><td>-</td><td>-</td><td></td></tr><tr><td>Ultrasonic cleaner</td><td>Derui ultrasonic device company</td><td>-</td><td></td></tr><tr><td>Soldering iron</td><td>-</td><td>-</td><td></td></tr></tbody></table>

a performance-testing platform for a conduction micropump with an fr-4 copper-clad electrode plate

Burada, bir iletim micropump ateşe dayanıklı cam takviyeli epoksi (FR-4) bakır kaplı laminat (CCL) üzerinde hazırlanan simetrik düzlemsel elektrot çiftleri ile imal edilmiştir. Odası boyutları etkisi ve tel micropump performansını araştırmak ve aseton çalışma sıvı kullanıldığında iletim pompa güvenilirliğini belirlemek için kullanılır. Test platformu farklı koşullar altında ve tel micropump performansını değerlendirmek için ayarlanır. Oda yüksekliği 0.2 mm olduğunda, pompa basıncı en yüksek değerine ulaşır.

Gerilim arttıkça Şekil 11' de gösterildiği gibi pompa basıncı ve artan hızları ayağa kalkın. 500 V gerilim ulaştığı zaman pompa basınç 1.100 ulaşır baba.
Pompa statik basınç odası Yükseklik 0.2 mm altında olduğunda artan Pompa Odası yüksekliği ile yükselir. Oda yüksekliği 0.2 mm olduğunda pompa performansı en yüksek noktası ulaşır. Oda yüksekliği artmaya devam ...

Watch this Scientific Journal Video about A Performance-testing Platform for a Conduction Micropump with an FR-4 Copper-clad Electrode Plate at JoVE.com

A Performance-testing Platform for a Conduction Micropump with an FR-4 Copper-clad Electrode Plate

Bu kağıt odası boyutları etkisi performansını test etmek için ateşe dayanıklı cam takviyeli epoksi (FR-4) bakır kaplı laminat (CCL) üzerinde simetrik düzlemsel elektrot kullanarak bir iletim micropump imalatı için bir protokol sunar bir iletim micropump.

Performans Test platformu ve tel Micropump FR-4 bakır kaplı elektrot plaka ile için

Here, a conduction micropump with symmetric planar electrode pairs prepared on flame-retardant glass-reinforced epoxy (FR-4) copper-clad laminate (CCL) is ...

a-performance-testing-platform-for-conduction-micropump-with-an-fr-4

Research

JoVE Journal

Bioengineering

5.9K Görüntüleme.  South China University of Technology. Bu kağıt odası boyutları etkisi performansını test etmek için ateşe dayanıklı cam takviyeli epoksi (FR-4) bakır kaplı laminat (CCL) üzerinde simetrik düzlemsel elektrot kullanarak bir iletim micropump imalatı için bir protokol sunar bir iletim micropump.

Video: A Performance-testing Platform for a Conduction Micropump with an FR-4 Copper-clad Electrode Plate

Real-Time DC-dynamic Biasing Method for Switching Time Improvement in Severely Underdamped Fringing-field Electrostatic MEMS Actuators

Mechanically underdamped electrostatic fringing-field MEMS actuators are well known for their fast switching operation in response to a unit step input bias voltage. However, the tradeoff for the improved switching performance is a relatively long settling time to reach each gap height in response to various applied voltages. Transient applied bias waveforms are employed to facilitate reduced switching times for electrostatic fringing-field MEMS actuators with high mechanical quality factors. Removing the underlying substrate of the fringing-field actuator creates the low mechanical damping environment necessary to effectively test the concept. The removal of the underlying substrate also a has substantial improvement on the reliability performance of the device in regards to failure due to stiction. Although DC-dynamic biasing is useful in improving settling time, the required slew rates for typical MEMS devices may place aggressive requirements on the charge pumps for fully-integrated on-chip designs. Additionally, there may be challenges integrating the substrate removal step into the back-end-of-line commercial CMOS processing steps. Experimental validation of fabricated actuators demonstrates an improvement of 50x in switching time when compared to conventional step biasing results. Compared to theoretical calculations, the experimental results are in good agreement.

The robust device design of fringing-field electrostatic MEMS actuators results in inherently low squeeze-film damping conditions and long settling times when performing switching operations using conventional step biasing. Real-time switching time improvement with DC-dynamic waveforms reduces the settling time of fringing-field MEMS actuators when transitioning between up-to-down and down-to-up states.

Real-Time DC-dinamik Öngerilimlenmesi Yöntem Ciddi Underdamped saçak-alanında Elektrostatik MEMS Eyleyiciler Zaman İyileştirme Anahtarlama

Mechanically underdamped electrostatic fringing-field MEMS actuators are well known for their fast switching operation in response to a unit step input ...

Mühendislik

Hollow Microneedle-based Sensor for Multiplexed Transdermal Electrochemical Sensing

The development of a minimally invasive multiplexed monitoring system for rapid analysis of biologically-relevant molecules could offer individuals suffering from chronic medical conditions facile assessment of their immediate physiological state. Furthermore, it could serve as a research tool for analysis of complex, multifactorial medical conditions. In order for such a multianalyte sensor to be realized, it must be minimally invasive, sampling of interstitial fluid must occur without pain or harm to the user, and analysis must be rapid as well as selective.
Initially developed for pain-free drug delivery, microneedles have been used to deliver vaccines and pharmacologic agents (e.g., insulin) through the skin.1-2 Since these devices access the interstitial space, microneedles that are integrated with microelectrodes can be used as transdermal electrochemical sensors. Selective detection of glucose, glutamate, lactate, hydrogen peroxide, and ascorbic acid has been demonstrated using integrated microneedle-electrode devices with carbon fibers, modified carbon pastes, and platinum-coated polymer microneedles serving as transducing elements.3-7,8
This microneedle sensor technology has enabled a novel and sophisticated analytical approach for in situ and simultaneous detection of multiple analytes. Multiplexing offers the possibility of monitoring complex microenvironments, which are otherwise difficult to characterize in a rapid and minimally invasive manner. For example, this technology could be utilized for simultaneous monitoring of extracellular levels of, glucose, lactate and pH,9 which are important metabolic indicators of disease states7,10-14 (e.g., cancer proliferation) and exercise-induced acidosis.15

This article details the construction of a multiplexed microneedle-based sensor. The device is being developed for in situ sampling and electrochemical analysis of multiple analytes in a rapid and selective manner. We envision clinical medicine and biomedical research uses for these microneedle-based sensors.

Multiplexed Transdermal Elektrokimyasal Algılama Hollow microneedle tabanlı Sensör

The development of a minimally invasive multiplexed monitoring system for rapid analysis of biologically-relevant molecules could offer individuals ...

Biyomühendislik

High Throughput Microfluidic Rapid and Low Cost Prototyping Packaging Methods

In this work, 3 different packaging and assembly techniques are presented. They can be classified into two categories: one-time use and reusable packaging techniques.
The one-time use packaging technique employs UV-based and temperature curing epoxies to connect microtubes to access holes, wire-bonding for integrated circuit connections, and silver epoxy for electrical connections. This method is based on a robust assembly technique that can support relatively high pressure close to 1 psi and does not need any support to strengthen the microfluidic architecture.
Reusable packaging techniques consist of PDMS-based microtube interconnectors and anisotropic adhesive films for electrical connections. These devices are more sensitive and fragile. Consequently, Plexiglas support is added to the microfluidic structure to improve the electrical contact when anisotropic adhesive films are used, and also to strengthen the microfluidic architecture. In addition, a micromanipulator is needed to maintain tubes while using a thin PDMS layer to connect them to the access holes. Different PDMS layer thicknesses, ranging from 0.45-3 mm, are tested to compare the best adherence versus injection rates. Applied injection rates are varied from 50-300 &#956;l/hr for 0.45-3 mm PDMS layers, respectively. These techniques are mainly applicable for low-pressure applications. However, they can be extended for high-pressure ones through plasma-oxygen process to permanently seal the PDMS to glass substrates. The main advantage of this technique, besides the fact that it is reusable, consists of keeping the device observable when the microchannel length is very short (in the range of 3 mm or lower).

In this article we describe different techniques for microfluidic rapid prototyping platforms. The proposed techniques are based on ultraviolet (UV) sensitive and temperature curing epoxies, polydimethylsiloxane (PDMS) based tubing, wire-bonding, and anisotropic adhesive films. The assembling procedures presented are developed for both one-time use devices as well as reusable microfluidic systems.

In this work, 3 different packaging and assembly techniques are presented. They can be classified into two categories: one-time use and reusable packaging ...

A Microfluidic Platform for Precision Small-volume Sample Processing and Its Use to Size Separate Biological Particles with an Acoustic Microdevice

A major advantage of microfluidic devices is the ability to manipulate small sample volumes, thus reducing reagent waste and preserving precious sample. However, to achieve robust sample manipulation it is necessary to address device integration with the macroscale environment. To realize repeatable, sensitive particle separation with microfluidic devices, this protocol presents a complete automated and integrated microfluidic platform that enables precise processing of 0.15&#8211;1.5 ml samples using microfluidic devices. Important aspects of this system include modular device layout and robust fixtures resulting in reliable and flexible world to chip connections, and fully-automated fluid handling which accomplishes closed-loop sample collection, system cleaning and priming steps to ensure repeatable operation. Different microfluidic devices can be used interchangeably with this architecture. Here we incorporate an acoustofluidic device, detail its characterization, performance optimization, and demonstrate its use for size-separation of biological samples. By using real-time feedback during separation experiments, sample collection is optimized to conserve and concentrate sample. Although requiring the integration of multiple pieces of equipment, advantages of this architecture include the ability to process unknown samples with no additional system optimization, ease of device replacement, and precise, robust sample processing.

This protocol describes a system architecture for performing automated small volume (0.15&#8211;1.5 ml) particle separations using a microfluidic device, and discusses methods to optimize acoustofluidic device performance and operation.

Bir mikroakışkan Hassas Küçük hacimli Numune İşleme Platformu ve Akustik mikrocihazda Ayrı Biyolojik Parçacıklar Boyutu Kullanımı

A major advantage of microfluidic devices is the ability to manipulate small sample volumes, thus reducing reagent waste and preserving precious sample. ...

Fabrication and Characterization of Thickness Mode Piezoelectric Devices for Atomization and Acoustofluidics

We present a technique to fabricate simple thickness mode piezoelectric devices using lithium niobate (LN). Such devices have been shown to atomize liquid more efficiently, in terms of &#64258;ow rate per power input, than those that rely on Rayleigh waves and other modes of vibration in LN or lead zirconate titanate (PZT). The complete device is composed of a transducer, a transducer holder, and a &#64258;uid supply system. The fundamentals of acoustic liquid atomization are not well known, so techniques to characterize the devices and to study the phenomena are also described. Laser Doppler vibrometry (LDV) provides vibration information essential in comparing acoustic transducers and, in this case, indicates whether a device will perform well in thickness vibration. It can also be used to &#64257;nd the resonance frequency of the device, though this information is obtained more quickly via impedance analysis. Continuous &#64258;uid atomization, as an example application, requires careful &#64258;uid flow control, and we present such a method with high-speed imaging and droplet size distribution measurements via laser scattering.

Fabrication of piezoelectric thickness mode transducers via direct current sputtering of plate electrodes on lithium niobate is described. Additionally, reliable operation is achieved with a transducer holder and &#64258;uid supply system and characterization is demonstrated via impedance analysis, laser doppler vibrometry, high-speed imaging, and droplet size distribution using laser scattering.

Atomizasyon ve Acoustofluidics için Kalınlık Modu Piezoelektrik Cihazların İmalatı ve Karakterizasyonu

We present a technique to fabricate simple thickness mode piezoelectric devices using lithium niobate (LN). Such devices have been shown to atomize liquid ...

Dry Film Photoresist-based Electrochemical Microfluidic Biosensor Platform: Device Fabrication, On-chip Assay Preparation, and System Operation

In recent years, biomarker diagnostics became an indispensable tool for the diagnosis of human disease, especially for the point-of-care diagnostics. An easy-to-use and low-cost sensor platform is highly desired to measure various types of analytes (e.g., biomarkers, hormones, and drugs) quantitatively and specifically. For this reason, dry film photoresist technology - enabling cheap, facile, and high-throughput fabrication - was used to manufacture the microfluidic biosensor presented here. Depending on the bioassay used afterwards, the versatile platform is capable of detecting various types of biomolecules. For the fabrication of the device, platinum electrodes are structured on a flexible polyimide (PI) foil in the only clean-room process step. The PI foil serves as a substrate for the electrodes, which are insulated with an epoxy-based photoresist. The microfluidic channel is subsequently generated by the development and lamination of dry film photoresist (DFR) foils onto the PI wafer. By using a hydrophobic stopping barrier in the channel, the channel is separated into two specific areas: an immobilization section for the enzyme-linked assay and an electrochemical measurement cell for the amperometric signal readout.
The on-chip bioassay immobilization is performed by the adsorption of the biomolecules to the channel surface. The glucose oxidase enzyme is used as a transducer for electrochemical signal generation. In the presence of the substrate, glucose, hydrogen peroxide is produced, which is detected at the platinum working electrode. The stop-flow technique is applied to obtain signal amplification along with rapid detection. Different biomolecules can quantitatively be measured by means of the introduced microfluidic system, giving an indication of different types of diseases, or, in regard to therapeutic drug monitoring, facilitating a personalized therapy.

A microfluidic biosensor platform was designed and fabricated using low-cost dry film photoresist technology for the rapid and sensitive quantification of various analytes. This single-use system allows for the electrochemical readout of on-chip-immobilized enzyme-linked assays by means of the stop-flow technique.

Kuru zar elektrokimyasal mikrosıvısal Biyoalgılayıcı fotorezist tabanlı Platform: Cihaz imalat, On-chip tahlil hazırlama ve sistemin çalışması

In recent years, biomarker diagnostics became an indispensable tool for the diagnosis of human disease, especially for the point-of-care diagnostics. An ...

Fabrication and Validation of an Organ-on-chip System with Integrated Electrodes to Directly Quantify Transendothelial Electrical Resistance

Organs-on-chips, in vitro models involving the culture of (human) tissues inside microfluidic devices, are rapidly emerging and promise to provide useful research tools for studying human health and disease. To characterize the barrier function of cell layers cultured inside organ-on-chip devices, often transendothelial or transepithelial electrical resistance (TEER) is measured. To this end, electrodes are usually integrated into the chip by micromachining methods to provide more stable measurements than is achieved with manual insertion of electrodes into the inlets of the chip. However, these electrodes frequently hamper visual inspection of the studied cell layer or require expensive cleanroom processes for fabrication. To overcome these limitations, the device described here contains four easily integrated electrodes that are placed and fixed outside of the culture area, making visual inspection possible. Using these four electrodes the resistance of six measurement paths can be quantified, from which the TEER can be directly isolated, independent of the resistance of culture medium-filled microchannels. The blood-brain barrier was replicated in this device and its TEER was monitored to show the device applicability. This chip, the integrated electrodes and the TEER determination method are generally applicable in organs-on-chips, both to mimic other organs or to be incorporated into existing organ-on-chip systems.

This publication describes the fabrication of an organ-on-chip device with integrated electrodes for direct quantification of transendothelial electrical resistance (TEER). For validation, the blood-brain barrier was mimicked inside this microfluidic device and its barrier function was monitored. The presented methods for electrode integration and direct TEER quantification are generally applicable.

İmalat ve Organ-on-chip sistemin doğrudan Transendothelial elektrik direncini ölçmek için entegre elektrotlar ile doğrulama

Organs-on-chips, in vitro models involving the culture of (human) tissues inside microfluidic devices, are rapidly emerging and promise to provide useful ...

Mechano-Node-Pore Sensing: A Rapid, Label-Free Platform for Multi-Parameter Single-Cell Viscoelastic Measurements

Cellular mechanical properties are involved in a wide variety of biological processes and diseases, ranging from stem cell differentiation to cancer metastasis. Conventional methods for measuring these properties, such as atomic force microscopy (AFM) and micropipette aspiration (MA), capture rich information, reflecting a cell's full viscoelastic response; however, these methods are limited by very low throughput. High-throughput approaches, such as real-time deformability cytometry (RT-DC), can only measure limited mechanical information, as they are often restricted to single-parameter readouts that only reflect a cell's elastic properties. In contrast to these methods, mechano-node-pore sensing (mechano-NPS) is a flexible, label-free microfluidic platform that bridges the gap in achieving multi-parameter viscoelastic measurements of a cell with moderate throughput. A direct current (DC) measurement is used to monitor cells as they transit a microfluidic channel, tracking their size and velocity before, during, and after they are forced through a narrow constriction. This information (i.e., size and velocity) is used to quantify each cell's transverse deformation, resistance to deformation, and recovery from deformation. In general, this electronics-based microfluidic platform provides multiple viscoelastic cell properties, and thus a more complete picture of a cell's mechanical state. Because it requires minimal sample preparation, utilizes a straightforward electronic measurement (in contrast to a high-speed camera), and takes advantage of standard soft lithography fabrication, the implementation of this platform is simple, accessible, and adaptable to downstream analysis. This platform's flexibility, utility, and sensitivity have provided unique mechanical information on a diverse range of cells, with the potential for many more applications in basic science and clinical diagnostics.

Presented here is a method to mechanically phenotype single cells using an electronics-based microfluidic platform called mechano-node-pore sensing (mechano-NPS). This platform maintains moderate throughput of 1-10 cells/s while measuring both the elastic and viscous biophysical properties of cells.

Mekano-Düğüm-Gözenek Algılama: Çok Parametreli Tek Hücreli Viskoelastik Ölçümler için Hızlı, Etiketsiz Bir Platform

Cellular mechanical properties are involved in a wide variety of biological processes and diseases, ranging from stem cell differentiation to cancer ...

Genlik Modülasyonlu Elektrodeformasyon ile RBC'lerin Mekanik Yorulma Testi

Amplitude-Modulated Electrodeformation to Evaluate Mechanical Fatigue of Biological Cells

Red blood cells (RBCs) are known for their remarkable deformability. They repeatedly undergo considerable deformation when passing through the microcirculation. Reduced deformability is seen in physiologically aged RBCs. Existing techniques to measure cell deformability cannot easily be used for measuring fatigue, the gradual degradation in cell membranes caused by cyclic loads. We present a protocol to evaluate mechanical degradation in RBCs from cyclic shear stresses using amplitude shift keying (ASK) modulation-based electrodeformation in a microfluidic channel. Briefly, the interdigitated electrodes in the microfluidic channel are excited with a low voltage alternating current at radio frequencies using a signal generator. RBCs in suspension respond to the electric field and exhibit positive dielectrophoresis (DEP), which moves cells to the electrode edges. Cells are then stretched due to the electrical forces exerted on the two cell halves, resulting in uniaxial stretching, known as electrodeformation. The level of shear stress and the resultant deformation can be easily adjusted by changing the amplitude of the excitation wave. This enables quantifications of nonlinear deformability of RBCs in response to small and large deformations at high throughput. Modifying the excitation wave with the ASK strategy induces cyclic electrodeformation with programmable loading rates and frequencies. This provides a convenient way for the characterization of RBC fatigue. Our ASK-modulated electrodeformation approach enables, for the first time, a direct measurement of RBC fatigue from cyclic loads. It can be used as a tool for general biomechanical testing, for analyses of cell deformability and fatigue in other cell types and diseased conditions, and can also be combined with strategies to control the microenvironment of cells, such as oxygen tension and biological and chemical cues.

Yazar Spotlight: Elektrodeformasyon Davranışlarını Modüle Ederek Dolaşımdaki Hücrelerin Biyomekaniğinin İncelenmesi 

Presented here is a protocol for mechanical fatigue testing in the case of human red blood cells using an amplitude-modulated electrodeformation approach. This general approach can be used to measure the systematic changes in morphological and biomechanical characteristics of biological cells in a suspension from cyclic deformation.