Name: fabrication of 3d carbon microelectromechanical systems (c-mems)
Uploaded: 2017-06-17T13:00:00.000+00:00
Duration: 8 min 1 s
Description: Watch this Scientific Journal Video about Fabrication of 3D Carbon Microelectromechanical Systems C-MEMS at JoVE.com

Diese Arbeit wurde von Technologico de Monterrey und der University of California in Irvine unterstützt.

1. 3D Mensch-Haar-abgeleitete Kohlenstoff-Struktur-Herstellung HINWEIS: Persönliche Schutzausrüstung verwenden. Befolgen Sie die Laboranweisungen, um die Instrumente zu benutzen und im Labor zu arbeiten. <ol><li> Bereiten Sie gesammeltes menschliches Haar vor, indem Sie es mit DI-Wasser waschen und es mit N 2 -Gas trocknen. </li><li> Die Haare wie gewünscht anordnen, wie z. B. in parallelen Strängen, kreuzen, mit zwei zusammengewickelten Haaren usw. </li><li> Befestigen Sie die Haare auf einem Siliziumsubstrat mit SU8 oder halten Sie sie direkt in einem keramischen Boot. </li><li> Legen Sie das mit Haaren versehene Siliziumsubstrat oder Boot in einen Ofen. </li><li> Schalten Sie den Ofen ein und öffnen Sie das Ventil eines Inertgases (N 2 ). HINWEIS: Die optimale Gasdurchflussmenge ist abhängig vom Volumen des Ofenrohres. Für ein Röhrenvolumen von 6 L wurde eine 6 L / min-Durchflussmenge angelegt. Um eine vollständig inerte Umgebung im Ofenrohr herzustellen, wurde eine Gasströmungsrate 1,5 mal höher als das optimale Gas fNiedrige Rate wurde für die ersten 15 min angewendet. </li><li> Stellen Sie die Parameter ein, einschließlich der maximalen Pyrolysetemperatur, der Temperaturrampenrate und der Inertgasdurchflussrate und führen Sie den Ofen aus. <ol><li> Zum Beispiel erhöhen Sie die Temperatur von Raumtemperatur auf 300 ° C bei einer 5 ° C / min Rampenzahl. Halten Sie es bei 300 ° C für 1 h zur Stabilisierung. Weiterhin die Temperatur auf 900 ° C erhöhen und für 1 h mehr für die Karbonisierung aufrechterhalten. </li><li> Den Ofen auf 300 ° C mit einer Geschwindigkeit von 10 ° C / min abkühlen und den Heizer ausschalten, da die kontrollierte Kühlung nach 300 ° C nicht erforderlich ist. Lassen Sie die Proben in den Ofen, bis die Temperatur Raumtemperatur nur durch N 2 fließt. </li></ol></li><li> Schalten Sie den Ofen und den Gasfluss nach Beendigung des Pyrolyseprozesses aus. </li><li> Nehmen Sie die Proben aus dem Ofen. </li></ol> 2. 3D-Polymerstruktur-Fertigung: Photolithographie <ol><li> DesEntwerbe ein 2D-Layout der gewünschten 3D-Photoresiststruktur unter Verwendung eines geeigneten Softwarepakets und bereite die gedruckte Maske ( dh eine Polyethylen-Photofilmmaske) vor. HINWEIS: Ein kommerzieller Service wurde verwendet, um das Design gedruckt zu bekommen. Die Größe der Maske hängt in der Regel vom Design ab. </li><li> In einem sauberen Laboratorium zwei Heizplatten einschalten und die Temperaturen auf 65 ° C bzw. 95 ° C einstellen. </li><li> Schalten Sie einen Schleuderbeschichter und eine Vakuumpumpe ein. Stellen Sie sicher, dass die Vakuumpumpe über ein Rohr mit dem Spinnkopf verbunden ist. </li><li> Legen Sie die Parameter des zweistufigen Spins fest, z. B. die Spinngeschwindigkeit, die Rampe und die Dauer. Für den ersten Schritt die Spinngeschwindigkeit auf 500 U / min, die Rampe auf 100 U / min und die Schleuderzeit auf 10 s einstellen, um den Schleuderzyklus zu beginnen. Für den nächsten Schritt die Spinngeschwindigkeit auf 1.000 U / min, die Rampe auf 100 U / min und die Spinzeit auf 30 s einstellen, um den Photoresist gleichmäßig zu verbreiten. </li><li> Legen Sie ein Substrat ( dh ein 4 Zoll x 4 Zoll und 5501, m ± 25 μm dicker Si-Wafer mit einer 1 μm dicken SiO 2 -Schicht) in der Mitte des Halters. </li><li> Setzen Sie das lichtempfindliche Polymer (dh den SU8-Photoresist) direkt auf die Mitte des Substrats ein. Verwenden Sie genug, um die Oberfläche zu bedecken. </li><li> Drücken Sie die Taste &quot;Vakuum&quot;, um das Substrat zu halten. </li><li> Drücken Sie die &quot;Run&quot; -Taste, um das Substrat mit SU8 zu beschichten und eine Enddicke von 250 μm zu erreichen. </li><li> Nach Beendigung des Spinnvorgangs drücken Sie erneut die Taste &quot;Vakuum&quot;, um das beschichtete Substrat aus dem Halter zu lösen. </li><li> Halten Sie das beschichtete Substrat sorgfältig mit einer Pinzette, um die Oberfläche glatt und sauber zu halten. Übertragen Sie das Substrat direkt auf die Heizplatte bei 65 ° C Temperatur für 6 min und dann auf die Heizplatte bei 95 ° C Temperatur für 40 min (weiches Backen). HINWEIS: Das Backen bei 65 ° C ist erforderlich, um die langsame Verdampfung des Lösungsmittels zu gewährleisten, was zu einer besseren Beschichtung und einer besseren Haftung führtO das Substrat, während das Backen bei 95 ° C das SU8 weiter verdichtet. </li><li> Drücken Sie in der Zwischenzeit den Schalter, um das UV-Belichtungssystem einzuschalten und stellen Sie die Zeit der Belichtung mit &quot;12 s&quot; mit der Set-Taste im System ein. HINWEIS: Für eine 250 μm dicke SU8-Schicht muss die Belichtungsenergie 360 ​​mJ / cm 2 betragen. </li><li> Sobald der Backschritt (Schritt 2.10) abgeschlossen ist, setzen Sie das Substrat in das UV-Belichtungssystem und legen Sie die bedruckte Seite einer Fotomaske (ab Schritt 2.1) darauf. Benutze den ganzen Maskenbereich, um das beschichtete Substrat zu bedecken und sanft zu drücken, um sicherzustellen, dass es keine Lücke zwischen Maske und Substrat gibt. </li><li> Setzen Sie das SU8-beschichtete Substrat durch die Photomaske mit vordefinierten UV-Einstellungen auf UV-Strahlung aus. </li><li> Das Substrat erneut erhitzen, indem man es direkt auf die Heizplatte bei 65 ° C für 5 min und bei 95 ° C für 14 min für einen Nachbelichtungs-Backen (PEB) platziert. HINWEIS: Der PEB erhöht den Vernetzungsgrad in den UV-exponierten Bereichen und macht denBeschichtung im Lösungsschritt widerstandsfähiger gegenüber Lösungsmitteln. </li><li> Entfernen Sie die unbelichteten Photoresistregionen, indem Sie das Substrat in die dafür vorgesehene Entwicklerlösung tauchen, für 20 min in ein Becherglas gegeben. Die Lösung sorgfältig schütteln (sorgfältig), um die vollständige Entfernung der unbelichteten Resistbereiche zu gewährleisten. </li><li> Trocknen Sie die entwickelten Strukturen, indem Sie das Substrat halten und Stickstoff oder Druckluft aufblasen. </li><li> Untersuche den Wafer unter einem Mikroskop mit 50facher Vergrößerung, um die auf den Photoresist übertragenen Muster mit den gewünschten Mustern zu vergleichen. </li></ol> 3. 3D-Kohlenstoffstruktur-Herstellung: Pyrolyse <ol><li> Legen Sie die mit der Photolithographie hergestellten Proben (Schritte 2.1-2.17) in einen unter Druck stehenden, offenen Rohrofen. </li><li> Schalten Sie den Ofen ein und stellen Sie die Parameter für die Pyrolyse ein, wie oben in Schritt 1 erwähnt. Wiederholen Sie den Vorgang ab Schritt 1.6-1.8. </li><li> Behandeln Sie die Proben sorgfältig mit Pinzetten und gehen Sie zu charakterisierenAtion </li></ol>

<ol>
	<li>Wang, C., Jia, G., Taherabadi, L. H., Madou, M. 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+novel+method+for+the+fabrication+of+high-aspect+ratio+C-MEMS+structures.">A novel method for the fabrication of high-aspect ratio C-MEMS structures.</a> J Microelectromech Syst. 14 (2), 348-358 (2005).</li><li>Jong, K. P. D., Geus, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Carbon+nano&#64257;bers:+catalytic+synthesis+and+applications.">Carbon nano&#64257;bers: catalytic synthesis and applications.</a> Catal Rev Sci Eng. 42, 481-510 (2000).</li><li>Elrouby, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrochemical+applications+of+carbon+nanotube.">Electrochemical applications of carbon nanotube.</a> J Nano Adv Mat. 1 (1), 23-38 (2013).</li><li>Baughman, R. H., Zakhidov, A. A., Heer, W. A. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Carbon+nanotubes-the+route+toward+applications.">Carbon nanotubes-the route toward applications.</a> Science. 297, 787-792 (2002).</li><li>Kumar, R., Singh, R. K., Singh, D. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Natural+and+waste+hydrocarbon+precursors+for+the+synthesis+of+carbon+based+nanomaterials:+graphene+and+CNTs.">Natural and waste hydrocarbon precursors for the synthesis of carbon based nanomaterials: graphene and CNTs.</a> Renew Sustain Energy Rev. 58, 976-1006 (2016).</li><li>Afre, R. A., Soga, T., Jimbo, T., Kumar, M., Ando, Y., Sharon, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Carbon+nanotubes+by+spray+pyrolysis+of+turpentine+oil+at+different+temperatures+and+their+studies.">Carbon nanotubes by spray pyrolysis of turpentine oil at different temperatures and their studies.</a> Micropor Mesopor Mater. (1-3), 184-190 (2006).</li><li>Sharma, S., Kalita, G., Hirano, R., Hayashi, Y., Tanemura, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+gas+composition+on+the+formation+of+graphene+domain+synthesized+from+camphor.">Influence of gas composition on the formation of graphene domain synthesized from camphor.</a> Mater Lett. 93, 258-262 (2013).</li><li>Ghosh, P., Afre, R. A., Soga, T., Jimbo, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+simple+method+of+producing+single-walled+carbon+nanotubes+from+a+natural+precursor:+eucalyptus+oil.">A simple method of producing single-walled carbon nanotubes from a natural precursor: eucalyptus oil.</a> Mater Lett. 61 (17), 3768-3770 (2007).</li><li>Kumar, R., Tiwari, R., Srivastava, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Scalable+synthesis+of+aligned+carbon+nanotubes+bundles+using+green+natural+precursor:+neem+oil.">Scalable synthesis of aligned carbon nanotubes bundles using green natural precursor: neem oil.</a> Nanoscale Res Lett. 6 (1), 92-97 (2011).</li><li>Liang, Y., Wu, D., Fu, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Carbon+microfibers+with+hierarchical+porous+structure+from+electrospun+fiber-like+natural+biopolymer.">Carbon microfibers with hierarchical porous structure from electrospun fiber-like natural biopolymer.</a> Sci Rep. 3, 1-5 (2013).</li><li>Gupta, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+hair+"waste"+and+its+utilization:+gaps+and+possibilities.">Human hair "waste" and its utilization: gaps and possibilities.</a> J Waste Manag. 2014, 1-17 (2014).</li><li>Qian, W., Sun, F., Xu, Y., Qiu, L., Liu, C., Wang, S., Yan, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+hair-derived+carbon+flakes+for+electrochemical+supercapacitors.">Human hair-derived carbon flakes for electrochemical supercapacitors.</a> Energy Environ Sci. 7, 379-386 (2014).</li><li>Pramanick, B., Cadenas, L. B., Kim, D. M., Lee, W., Shim, Y. B., Martinez-Chapa, S. O., Madou, M. J., Hwang, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+hair-derived+hollow+carbon+microfibers+for+electrochemical+sensing.">Human hair-derived hollow carbon microfibers for electrochemical sensing.</a> Carbon. 107, 872-877 (2016).</li><li>Miura, N., Numaguchi, T., Yamada, A., Konagai, M., Shirakashi, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Room+temperature+operation+of+amorphous+carbon-based+single-electron+transistors+fabricated+by+beam-induced+deposition+techniques.">Room temperature operation of amorphous carbon-based single-electron transistors fabricated by beam-induced deposition techniques.</a> Jpn J Appl Phys. 37 (2), L423-L425 (1998).</li><li>Irie, M., Endo, S., Wang, C. L., Ito, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fabrication+and+properties+of+lateral+p-i-p+structures+using+single+crystalline+CVD+diamond+layers+for+high+electric+&#64257;eld+applications.">Fabrication and properties of lateral p-i-p structures using single crystalline CVD diamond layers for high electric &#64257;eld applications.</a> Diamond Rel Mater. 12, 1563-1568 (2003).</li><li>Tay, B. K., Sheeja, D., Yu, L. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On+stress+reduction+of+tetrahedral+amorphous+carbon+&#64257;lms+for+moving+mechanical+assemblies.">On stress reduction of tetrahedral amorphous carbon &#64257;lms for moving mechanical assemblies.</a> Diamond Rel Mater. 12 (2), 185-194 (2003).</li><li>Kamath, R. R., Madou, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-dimensional+carbon+interdigitated+electrode+arrays+for+redox-amplification.">Three-dimensional carbon interdigitated electrode arrays for redox-amplification.</a> Anal Chem. 86 (6), 2963-2971 (2014).</li><li>Sharma, S., Khalajhedayati, A., Rupert, T. J., Madou, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=SU8+derived+glassy+carbon+for+lithium+ion+batteries.">SU8 derived glassy carbon for lithium ion batteries.</a> ECS Trans. 61 (7), 75-84 (2014).</li><li>Kim, D., Pramanick, B., Salazar, A., Tcho, I. -. W., Madou, M. J., Jung, E. S., Choi, Y. -. K., Hwang, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=3D+carbon+electrode+based+triboelectric+nanogenerator.">3D carbon electrode based triboelectric nanogenerator.</a> Adv Mater Technol. 1 (8), 1-7 (2016).</li><li>Duarte, R. M., Gorkin, R. A., Samra, K. B., Madou, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+integration+of+3D+carbon-electrode+dielectrophoresis+on+a+CD-like+centrifugal+microfluidic+platform.">The integration of 3D carbon-electrode dielectrophoresis on a CD-like centrifugal microfluidic platform.</a> Lab Chip. 10 (8), 1030-1043 (2010).</li><li>Mund, K., Richter, G., Weidlich, E., Fahlstrom, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrochemical+properties+of+platinum,+glassy+carbon,+and+pyrographite+as+stimulating+electrodes.">Electrochemical properties of platinum, glassy carbon, and pyrographite as stimulating electrodes.</a> Pacing Clin Electrophysiol. 9 (6), 1225-1229 (1986).</li><li>Xua, H., Malladi, K., Wang, C., Kulinsky, L., Song, M., Madou, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Carbon+post-microarrays+for+glucose+sensors.">Carbon post-microarrays for glucose sensors.</a> Biosens Bioelectron. 23 (11), 1637-1644 (2008).</li><li>Sharma, S., Madou, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Micro+and+nano+patterning+of+carbon+electrodes+for+bioMEMS.">Micro and nano patterning of carbon electrodes for bioMEMS.</a> Bioinspir Biomim Nanobiomat. 1, 252-265 (2012).</li><li>Pramanick, B., Martinez-Chapa, S. O., Madou, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fabrication+of+biocompatible+hollow+microneedles+using+the+C-MEMS+process+for+transdermal+drug+delivery.">Fabrication of biocompatible hollow microneedles using the C-MEMS process for transdermal drug delivery.</a> ECS Trans. 72 (1), 45-50 (2016).</li></ol>

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In dieser Arbeit wurden die Verfahren zur Herstellung einer Vielzahl von Kohlenstoff-Mikrostrukturen auf der Basis der Pyrolyse von natürlichen Vorläufermaterialien oder photomusterisierten Polymerstrukturen beschrieben. Die Kohlenstoffmaterialien, die sowohl aus den herkömmlichen als auch aus nicht konventionellen C-MEMS / C-NEMS-Verfahren resultieren, sind typischerweise glasartige Kohlenstoffe. Glassy Carbon ist ein weit verbreitetes Elektrodenmaterial für die Elektrochemie und auch für Hochtemperaturanwendungen...

Carbon hat viele Allotrope und kann je nach Anwendungsfall eines der folgenden Allotrope ausgewählt werden: Kohlenstoff-Nanoröhrchen (CNTs), Graphit, Diamant, amorpher Kohlenstoff, Lonsdalion, Buckminsterfulleren (C 60 ), Fullerit (C 540 ), Fulleren ( C 70 ) und glasartigem Kohlenstoff 1 , 2 , 3 , 4 . Glasiger Kohlenstoff ist einer der am häufigsten verwendeten Allotrope wegen seiner physikalischen Eigenschaften, einschließlich der hohen Isotropie. Es hat auch folgende Eigenschaften: gute elektrische Leitfähigkeit, geringer Wärmeausdehnungskoeffizient und Gasundurchlässigkeit. Es wurde eine kontinuierliche Suche nach kohlenstoffreichen Vorläufermaterialien erhalten, um Kohlenstoffstrukturen zu erhalten. Diese Vorläufer können künstliche Materialien oder natürliche Produkte sein, die in bestimmten Formen verfügbar sind und sogar Abfallprodukte enthalten. Eine Vielzahl von micr<html> O / nanostrukturen werden über biologische oder umwelttechnische Prozesse in der Natur gebildet, was zu einzigartigen Merkmalen führt, die mit herkömmlichen Fertigungswerkzeugen extrem schwierig zu erstellen sind. Da die Musterbildung in diesem Fall natürlich stattfand, konnte die Synthese von Nanomaterialien unter Verwendung von Natur- und Abfall-Kohlenwasserstoff-Vorläufern unter Verwendung eines einfachen, einstufigen thermischen Zersetzungsprozesses in einer Inert- oder Vakuumatmosphäre, der Pyrolyse 5 , durchgeführt werden. Hochwertige Graphen, einwandige CNTs, mehrwandige CNTs und Kohlenstoffpunkte wurden durch thermische Zersetzung oder die Pyrolyse von pflanzlichen Vorläufern und Abfällen, einschließlich Samen, Fasern und Ölen, wie Terpentinöl, Sesamöl, hergestellt , Neemöl ( Azadirachta indica ), Eukalyptusöl, Palmöl und Jatrophaöl. Auch Kampferprodukte, Teebaum-Extrakte, Abfallnahrungsmittel, Insekten, Agroabfälle und Nahrungsmittelprodukte wurden 6 , 7 ,Ass = &quot;xref&quot;&gt; 8 , 9 Vor kurzem haben Forscher sogar Seidenkokons als Vorläufermaterial verwendet, um poröse Kohlenstoffmikrofasern herzustellen 10 . Das menschliche Haar, das gewöhnlich als Abfallmaterial angesehen wird, wurde vor kurzem von diesem Team benutzt. Es besteht aus etwa 91% Polypeptiden, die mehr als 50% Kohlenstoff enthalten; Der Rest sind Elemente wie Sauerstoff, Wasserstoff, Stickstoff und Schwefel 11 . Haar kommt auch mit einigen interessanten Eigenschaften, wie sehr langsamer Abbau, hohe Zugfestigkeit, hohe Wärmedämmung und hohe elastische Erholung. In letzter Zeit wurde es verwendet, um in den Superkondensatoren 12 eingesetzte Kohlenstoffflocken herzustellen und Hohlkohlenstoffmikrofasern für die elektrochemische Erfassung 13 zu erzeugen. Die Bearbeitung eines Schüttgutmaterials zur Herstellung dreidimensionaler (3D) Strukturen ist eine schwierige Aufgabe, da das Material sehr spröde ist. Fokussiertes IonAm 14 , 15 oder reaktives Ionenätzen 16 können in diesem Zusammenhang nützlich sein, aber es sind teure und zeitaufwändige Prozesse. Carbon-Mikroelektromechanik (C-MEMS) -Technologie, die auf der Pyrolyse von gemusterten Polymerstrukturen basiert, stellt eine vielseitige Alternative dar. In den vergangenen zwei Jahrzehnten haben C-MEMS und Carbon-Nanoelektromechanische Systeme (C-NEMS) aufgrund der einfachen und kostengünstigen Fertigungsschritte viel Aufmerksamkeit erlangt. Das herkömmliche C-MEMS-Herstellungsverfahren wird in zwei Schritten durchgeführt: (i) Strukturieren eines Polymervorläufers ( z. B. eines Photoresists) mit Photolithographie und (ii) Pyrolyse der gemusterten Strukturen. Ultraviolett (UV) -veränderbare Polymervorläufer, wie z. B. SU8-Photoresists, werden häufig verwendet, um Strukturen auf der Grundlage der Photolithographie zu bilden. Im Allgemeinen umfasst das Photolithographieverfahren Schritte für die Schleuderbeschichtung, das weiche Backen, die UV-Exposition, das Nachbacken und die EntwicklungLopment Im Fall von C-MEMS; Silizium; Siliciumdioxid; Siliciumnitrid; Quarz; Und in letzter Zeit wurden Saphir als Substrate verwendet. Die photostrukturierten Polymerstrukturen werden bei einer hohen Temperatur (800-1.100 ° C) in einer sauerstofffreien Umgebung carbonisiert. Bei diesen erhöhten Temperaturen in einem Vakuum oder einer inerten Atmosphäre werden alle Nicht-Kohlenstoff-Elemente entfernt, wobei nur Kohlenstoff übrig bleibt. Diese Technik ermöglicht die Erzielung hochwertiger, glasartiger Kohlenstoffstrukturen, die für viele Anwendungen sehr nützlich sind, einschließlich der elektrochemischen Erfassung 17 , des Energiespeichers 18 , der triboelektrischen Nanogenierung 19 und der elektrokinetischen Partikelmanipulation 20. Auch die Herstellung von 3D-Mikrostrukturen mit Hohe Aspektverhältnisse unter Verwendung von C-MEMS ist relativ einfach geworden und hat zu einer Vielzahl von Kohlenstoffelektrodenanwendungen 18 , 21 , </sup&gt; 22 , 23 , die oft Edelmetallelektroden ersetzen. In dieser Arbeit wird die jüngste Entwicklung eines einfachen und kostengünstigen Verfahrens zur Herstellung von Hohlkohlenstoff-Mikrofasern aus menschlichem Haar unter Verwendung nicht konventioneller C-MEMS-Technologie 13 eingeführt. Das herkömmliche SU8-Polymer-basierte C-MEMS-Verfahren wird hier ebenfalls beschrieben. Speziell wird das Herstellungsverfahren für hoch-Seitenverhältnis-Feststoffe und hohle SU8-Strukturen beschrieben 24.

<table><tbody><tr><td>SU8-2100</td><td>Microchem</td><td>Product number-Y1110750500L</td><td></td></tr><tr><td>Spinner</td><td>Laurell Technologies Corporation</td><td>Model-WS650HZB-23NPP/UD3</td><td></td></tr><tr><td>Hotplate</td><td>Torrey Pines Scientific</td><td>HS61</td><td></td></tr><tr><td>UV-exposer</td><td>Mercury Lamp, SYLVANIA</td><td>H44GS-100M, P/N-34-0054-01</td><td></td></tr><tr><td>Photomask</td><td>CAD/Art</td><td></td><td>No number</td></tr><tr><td>Developer&amp;nbsp;</td><td>Microchem</td><td>Y020100 4000L&amp;nbsp;</td><td></td></tr><tr><td>DI water system</td><td>Milli Q</td><td>ZOOQOVOTO</td><td></td></tr><tr><td>IPA</td><td>CTR Sientific</td><td>CTR 01244</td><td></td></tr><tr><td>N&lt;sub&gt;2&lt;/sub&gt; gas</td><td>AOC Mexico</td><td></td><td>No number</td></tr><tr><td>Furnace</td><td>PEO 601, ATV Technologie GMBH</td><td>Model-PEO 601, Serial no.-195</td><td></td></tr><tr><td>Si/SiO&lt;sub&gt;2&lt;/sub&gt;</td><td>Noel Technologies</td><td></td><td></td></tr></tbody></table>

fabrication of 3d carbon microelectromechanical systems (c-mems)

Eine breite Palette von Kohlenstoffquellen gibt es in der Natur, mit einer Vielzahl von Mikro- / Nanostruktur-Konfigurationen. Hier wird eine neuartige Technik zur Herstellung von langen und hohlen glasartigen Kohlenstoffmikrofasern aus menschlichen Haaren eingeführt. Die langen und hohlen Kohlenstoffstrukturen wurden durch die Pyrolyse von menschlichem Haar bei 900 ° C in einer N 2 -Atmosphäre hergestellt. Die Morphologie und die chemische Zusammensetzung der natürlichen und pyrolysierten menschlichen Haare wurden unter Verwendung von Rasterelektronenmikroskopie (SEM) bzw. elektronendispersiver Röntgenspektroskopie (EDX) untersucht, um die physikalischen und chemischen Veränderungen aufgrund der Pyrolyse zu schätzen. Raman-Spektroskopie wurde verwendet, um die glasartige Natur der Kohlenstoff-Mikrostrukturen zu bestätigen. Pyrolysierter Haarkohlenstoff wurde eingeführt, um die bedruckten Kohlenstoffelektroden zu modifizieren; Die modifizierten Elektroden wurden dann auf die elektrochemische Erfassung von Dopamin und Ascorbinsäure aufgebracht. Die Erfassungsleistung der modifizierten Sensoren wurde im Vergleich zum Unmodi verbessertFied Sensoren. Um die gewünschte Kohlenstoffstrukturkonstruktion zu erhalten, wurde eine Kohlenstoff-Mikro- / Nanoelektromechanische System- (C-MEMS / C-NEMS) -Technologie entwickelt. Das häufigste C-MEMS / C-NEMS-Herstellungsverfahren besteht aus zwei Schritten: (i) der Strukturierung eines kohlenstoffreichen Basismaterials, wie eines lichtempfindlichen Polymers, unter Verwendung von Photolithographie; Und (ii) Karbonisierung durch die Pyrolyse des gemusterten Polymers in einer sauerstofffreien Umgebung. Das C-MEMS / NEMS-Verfahren wurde weitgehend zur Entwicklung von mikroelektronischen Bauelementen für verschiedene Anwendungen eingesetzt, ua in Mikrobatterien, Superkondensatoren, Glukosesensoren, Gassensoren, Brennstoffzellen und triboelektrischen Nanogeneratoren. Hier werden die jüngsten Entwicklungen eines hochauflösenden Feststoff- und Hohlkohlenstoff-Mikrostrukturen mit SU8-Photoresists diskutiert. Die strukturelle Schrumpfung während der Pyrolyse wurde mittels konfokaler Mikroskopie und SEM untersucht. Raman-Spektroskopie wurde verwendet, um die Kristallinität der Struktur zu bestätigen, und der atomare Prozentsatz der Elemente preseNt im Material vor und nach der Pyrolyse wurde mit EDX gemessen.

Ein Schema des Herstellungsverfahrens für Menschenhaar-abgeleitete Hohlkohlenstoff-Mikrofasern ist in Fig. 1 gezeigt . Das karbonisierte menschliche Haar wurde durch SEM charakterisiert, um die Schrumpfung zu schätzen. Der Haardurchmesser schrumpfte von 82,88 ± 0,003 μm auf 31,42 ± 0,003 μm aufgrund der Pyrolyse. Rasterelektronenmikroskopische (SEM) -Bilder von verschiedenen Mustern, die mit Haaren abgeleitete Kohlenstoffmikrofasern hergestellt wurden,...

Watch this Scientific Journal Video about Fabrication of 3D Carbon Microelectromechanical Systems C-MEMS at JoVE.com

Fabrication of 3D Carbon Microelectromechanical Systems C-MEMS

Lange und hohle glasartige Kohlenstoffmikrofasern wurden auf der Basis der Pyrolyse eines Naturproduktes, menschliches Haar, hergestellt. Die beiden Herstellungsschritte von kohlenstoffmikroelektromechanischen und kohlenstoff-nanoelektromechanischen Systemen oder C-MEMS und C-NEMS sind: (i) Photolithographie eines kohlenstoffreichen Polymervorläufers und (ii) Pyrolyse des gemusterten Polymervorläufers.

Herstellung von 3D-Carbon-Mikroelektromechanischen Systemen (C-MEMS)

A wide range of carbon sources are available in nature, with a variety of micro-/nanostructure configurations. Here, a novel technique to fabricate long ...

fabrication-of-3d-carbon-microelectromechanical-systems-c-mems

Research

JoVE Journal

Engineering

Fabrication of 3D Carbon Microelectromechanical Systems (C-MEMS)

12.0K Aufrufe.  Tecnologico de Monterrey.  Lange und hohle glasartige Kohlenstoffmikrofasern wurden auf der Basis der Pyrolyse eines Naturproduktes, menschliches Haar, hergestellt. Die beiden Herstellungsschritte von kohlenstoffmikroelektromechanischen und kohlenstoff-nanoelektromechanischen Systemen oder C-MEMS und C-NEMS sind: (i) Photolithographie eines kohlenstoffreichen Polymervorläufers und (ii) Pyrolyse des gemusterten Polymervorläufers. 

Serie: Fabrication of 3D Carbon Microelectromechanical Systems C-MEMS

Fabrication, Densification, and Replica Molding of 3D Carbon Nanotube Microstructures

The introduction of new materials and processes to microfabrication has, in large part, enabled many important advances in microsystems, lab-on-a-chip devices, and their applications. In particular, capabilities for cost-effective fabrication of polymer microstructures were transformed by the advent of soft lithography and other micromolding techniques 1, 2, and this led a revolution in applications of microfabrication to biomedical engineering and biology. Nevertheless, it remains challenging to fabricate microstructures with well-defined nanoscale surface textures, and to fabricate arbitrary 3D shapes at the micro-scale. Robustness of master molds and maintenance of shape integrity is especially important to achieve high fidelity replication of complex structures and preserving their nanoscale surface texture. The combination of hierarchical textures, and heterogeneous shapes, is a profound challenge to existing microfabrication methods that largely rely upon top-down etching using fixed mask templates. On the other hand, the bottom-up synthesis of nanostructures such as nanotubes and nanowires can offer new capabilities to microfabrication, in particular by taking advantage of the collective self-organization of nanostructures, and local control of their growth behavior with respect to microfabricated patterns. 
Our goal is to introduce vertically aligned carbon nanotubes (CNTs), which we refer to as CNT "forests", as a new microfabrication material. We present details of a suite of related methods recently developed by our group: fabrication of CNT forest microstructures by thermal CVD from lithographically patterned catalyst thin films; self-directed elastocapillary densification of CNT microstructures; and replica molding of polymer microstructures using CNT composite master molds. In particular, our work shows that self-directed capillary densification ("capillary forming"), which is performed by condensation of a solvent onto the substrate with CNT microstructures, significantly increases the packing density of CNTs. This process enables directed transformation of vertical CNT microstructures into straight, inclined, and twisted shapes, which have robust mechanical properties exceeding those of typical microfabrication polymers. This in turn enables formation of nanocomposite CNT master molds by capillary-driven infiltration of polymers. The replica structures exhibit the anisotropic nanoscale texture of the aligned CNTs, and can have walls with sub-micron thickness and aspect ratios exceeding 50:1. Integration of CNT microstructures in fabrication offers further opportunity to exploit the electrical and thermal properties of CNTs, and diverse capabilities for chemical and biochemical functionalization 3.

We present methods for fabrication of patterned microstructures of vertically aligned carbon nanotubes (CNTs), and their use as master molds for production of polymer microstructures with organized nanoscale surface texture. The CNT forests are densified by condensation of solvent onto the substrate, which significantly increases their packing density and enables self-directed formation of 3D shapes.

Fabrication, Verdichtung, und Replica Molding von 3D-Carbon Nanotube Mikrostrukturen

The introduction of new materials and processes to microfabrication has, in large part, enabled many important advances in microsystems, lab-on-a-chip ...

Forschung

Ingenieurwesen

Microfabricated Platforms for Mechanically Dynamic Cell Culture

The ability to systematically probe in vitro cellular response to combinations of mechanobiological stimuli for tissue engineering, drug discovery or fundamental cell biology studies is limited by current bioreactor technologies, which cannot simultaneously apply a variety of mechanical stimuli to cultured cells. In order to address this issue, we have developed a series of microfabricated platforms designed to screen for the effects of mechanical stimuli in a high-throughput format. In this protocol, we demonstrate the fabrication of a microactuator array of vertically displaced posts on which the technology is based, and further demonstrate how this base technology can be modified to conduct high-throughput mechanically dynamic cell culture in both two-dimensional and three-dimensional culture paradigms.

In this protocol, we demonstrate the fabrication of a microactuator array of vertically displaced posts on which the technology is based, and how this base technology can be modified to conduct high-throughput mechanically dynamic cell culture in both two-dimensional and three-dimensional culture paradigms.

Mikrofabrizierten Plattformen für Mechanisch Dynamische Cell Culture

The ability to systematically probe in vitro cellular response to combinations of mechanobiological stimuli for tissue engineering, drug discovery or ...

Biotechnik

Micro-masonry for 3D Additive Micromanufacturing

Transfer printing is a method to transfer solid micro/nanoscale materials (herein called &#8216;inks&#8217;) from a substrate where they are generated to a different substrate by utilizing elastomeric stamps. Transfer printing enables the integration of heterogeneous materials to fabricate unexampled structures or functional systems that are found in recent advanced devices such as flexible and stretchable solar cells and LED arrays. While transfer printing exhibits unique features in material assembly capability, the use of adhesive layers or the surface modification such as deposition of self-assembled monolayer (SAM) on substrates for enhancing printing processes hinders its wide adaptation in microassembly of microelectromechanical system (MEMS) structures and devices. To overcome this shortcoming, we developed an advanced mode of transfer printing which deterministically assembles individual microscale objects solely through controlling surface contact area without any surface alteration. The absence of an adhesive layer or other modification and the subsequent material bonding processes ensure not only mechanical bonding, but also thermal and electrical connection between assembled materials, which further opens various applications in adaptation in building unusual MEMS devices.

This paper introduces a 3D additive micromanufacturing strategy (termed &#8216;micro-masonry&#8217;) for the flexible fabrication of microelectromechanical system (MEMS) structures and devices. This approach involves transfer printing-based assembly of micro/nanoscale materials in conjunction with rapid thermal annealing-enabled material bonding techniques.

Micro-Mauerwerk für 3D-Additive Mikroproduktion

Transfer printing is a method to transfer solid micro/nanoscale materials (herein called &#8216;inks&#8217;) from a substrate where they are generated to ...

Using Micro-Electro-Mechanical Systems (MEMS) to Develop Diagnostic Tools

Using Micro-Electro-Mechanical Systems MEMS to Develop Diagnostic Tools

I'm U De Mercy, I'm the principal investigator of Bio Stick MAMs in Medicine Labs. I did my PhD at Stanford University in electrical engineering. I did a postdoc at Harvard Medical School at MGH working on bio acoustic MAMs or mostly bio MAs.And now I'm continuing as a faculty at Harvard Medical School at Harvard MIT Health Sciences and Technology. And continuing with my research that I enjoy very much. The work that I did during my PhD was very much related to droplets and using acoustics to generate precise size droplets and control their location and position to deposit very sensitive polymers.Now we apply similar technologies to encapsulate cells in droplets and then position them on the surfaces for various applications in tissue engineering to print cells on the surfaces to pattern cells. Also, there are applications where you want to see that you can encapsulate few cells or a single cell or from the same population and to see the differences between the same population from one cell to another there being able to encapsulate cells in droplets at high throughput rates like 10, 000 cells per second kind of rates becomes very important and very useful to understand biological problems. So my research currently has two legs, I would say.One is this cell encapsulation work that I just talked about. How do we pack a cell in a droplet that's, and how can we do this repeatedly and reliably and without harming the cells? So after the cell is ejected or encapsulated in the droplet, we should be able to precisely located on a surface the cell should be functional and alive and viable.It shouldn't be harmed by the effects of ejection and so forth. So currently we have a system where we use acoustic drop focused waves to generate these droplets from open pools where we can encapsulate down to single cells in these really small droplets that are comparable to the cell size. That's very exciting in terms of applying this to cell printing and tissue engineering.The other side of my research is again using these MAMs micro electromechanical system technologies to develop low cost diagnostic tools. Mostly this research uses microfluidic approaches where we can introduce whole blood, very small volumes such as blood from a prick finger prick, less than 10 microliters that you can introduce to a chip. And from that blood we can encapsulate or you can capture certain sub-cellular populations from whole blood.Why is this important? Why should this be cheap for global health applications On top of the mountain in Africa, you want to be able to tell for a HIV patient, for instance, how many CD four T lymphocytes this patient has. Because World Health Organization says that below 200 CD four cells per microliter, you have to start treating the patients In the developed world, you use hundreds of thousands dollars of vert flow cytometers to be able to get this data.And it takes of course time to use and skill of course to be able to use these like huge table size machines. Our small chip can be introduced this small finger brick 10 microliters of whole blood and it'll capture the CD four cells using the surface protein affinities. And then you can rapidly count these cells that are captured because you know that there are CD four cells which are attached to CD four proteins antibodies on the surface of the chip.By controlling the flow rates and shear, you can make sure that the specificity and efficiency for these cell types are optimized. And there's of course always non specific binding, but by our sheer approaches we minimize these effects and make sure that between plus minus 10%errors, which is sufficient to make a diagnostic or prognostic decision on top mountain in Africa. So this has interesting applications for global health as well as these low cost techniques that are disposable can impact the developed world because now these fast blood tests which are really low cost can impact the tests that we use in the developed world.If they're optimized to higher levels of efficiency and specificity, which our initial data shows that they can be, then it'll definitely impact our lives. When I first finished my PhD, I knew more about microfluidics and that in MAMs more than anything else I could see, especially with the droplet application, I could see that if I could print cells and encapsulate cells or manipulate the few cells, single cells, that it'll have great applications in biotechnology area. And I was very interested in working on things that will actually impact people's lives.I used to apply these technologies to semiconductor industry, but then I wanted to to be useful directly to people. So I, that's what directed me towards problems in healthcare. And then that's why I made a big shift and came to a hospital, mass general hospital to the postdoc.And there, you know, I got exposed more and more to problems and it seems, and it's all clear that one of the biggest problems of the world today is global health and there comes illnesses like tuberculosis, HIV that kills thousands of people per day. And these people die not because the drugs are not there, but because there aren't enough diagnostic tools which is much more expensive than the existing drugs. So I know the technology side of the things very well.I get, I got exposed to the biological problems and the more I learned about them, the more I could see that I could make an impact. And that's how it all grew from there. And it's still continuing now.Like I seen biotechnology and in medicine there are like so many problems that actually directly cause our result into loss of people's lives and the technologies, the technology aspect of it and being able to apply it to real world medical problems is a great, I think path to follow. This is like how this whole biotechnology area I think is kind of growing and it's becoming very impactful. If you think about it, HIV cancer, those are big killers in the world.And current micro technologies, current approaches could maybe benefit from early detection of cancer by capturing these cells from blood or making it really cheap, which will make it available to masses. So all these things coming together, I think this whole microtechnology applications in healthcare in medicine could impact the future of human beings. So that's how all these things kind of come together I guess.And being in the Harvard MIT health sciences and technology where on one end you have the technology and on the other end you direct aspect, direct access to patients, direct access to doctors in Brigham and Women's Hospital where I work is a great environment. cause every person that you talk to have their problems and you could maybe it's coming from a different background, provide interesting solutions to those existing real world problems. So this is, I think how I see the whole perspective of how these medical problems meet the technology side.And we try to impact people's lives in a positive way. In single cell cap encapsulation or in cell encapsulation, the major challenge is to be able to encapsulate reliably and repeatably single cells. So you're ejecting 10, 000 hundred thousand cells per second.And how do you make sure that each droplet that you eject has a single cell? This statistics where you are changing the droplet size and minimizing the, optimizing the cell size over the droplet size, which goes into the old problem of packing spheres in a volume and what is the most efficient way to do it. So that's the biggest challenge in the cell printing area for from the technological side.The other aspect of it is now you can say print and precisely locate these cells. How can you generate these three dimensional tissues and how can you keep them alive and how can you transplant them? There comes in the biological end of the problems where you want to now exactly mimic the tissue.We have current approaches to be able to print an eyelet, a pancreas eyelet, and to be able to print using smooth muscle cells, a bladder tissue, directly mimicking what is in human or red bladder so that then we can make this tissue and test how well it performs compared to the real world existing native tissues. So that's the major challenge I guess by taking these novel technologies, how can you make this the ideal tissue that can be replaced, that can be transplanted, that's the, you know, biggest problem from the beginning because the control on single cell gives you the capability to precisely locate them. And then how do you kind of grow it from there?So it's something transplantable there where the impact of human life comes. So that's on that end, what the challenges are in the tissue engineering side of the things in southern encapsulation and in diagnostics using microfluidics, the challenge is to be able to capture a cell out of billions of cells. It's like you have a sugar particle in a salt can and you're trying to pull out that sugar particle and that's like one in a billion.So you, you're processing microliters to milliliters of whole blood and you want to be able to specifically and efficiently without any technological problems like clogging or any biological problems like non-specific binding, you want to be able to isolate at one cell out of billion cells in one microliter of whole blood, you have a few millions of cells. And for the CD four T lymphocyte case in that one microliter, we are after about thousand cells per microliter. So it's like one cell in a thousand kind of a problem where we have shown that it's doable.But when you want to go after circulating tumor cells for cancer, then the challenge becomes one in a billion. So to some summarize it, the challenge is how do we capture this one cell out of billions of other cells around it? And what is the technological aspects?What are the flow rates? What is the device design? What, what are the flow rates?What, what are the volumes of blood that has to be processed and how do you make sure that the cells you capture are the ones that you actually wanted to capture? All these aspects kind formed the whole challenge that can be summarized in one sentence, which is how do you capture this one rare cell out of billion others? So it's really a needle in a haystack kind of problem, which is exciting.And I think this is moving the technologies forward to address these problems is the current technological challenge. Being able to bring them to a level where they do the job that they're supposed to do is one thing. And then taking it to the clinic and making it a product has all different expertise such as being able to start a company, being able to patent these things and all those other aspects come into the picture.And I think we as scientists primarily don't have all of those skills that takes the products from desktop to products. So there comes in again, the importance of collaborations with people who have different backgrounds. And there are many technologies out there that I think could be very impactful and useful.They sometimes don't make it to the clinic or to the use of humankind either because it just didn't happen, wasn't the right time or other effects came into the picture that I just talked about. Or sometimes there isn't a direct link that you couldn't see that the technology could actually solve that problem. And the person who deals with the problem, or let's say the biologists or people in medicine are used to doing it one way for many years.And the people on the technology side mostly if you're not having a biotechnology focus, are not aware of the problems in medicine. So bringing these two sides together is a serious interdisciplinary research. And I think in the past years, the whole emphasis both at NIH level and that we see in research labs and universities is to generate interdisciplinary research.So people end up getting PhDs where they have to know multiple fields. For instance, for my PhD, I had to know acoustics, I had to know mems, I had to know microfluidics and I had to apply this for polymers. So now you see kinda very depth of knowledge in one field where you had to know actually three other fields quite well to be able to solve that problem.So I think the answer is in interdisciplinary research combined with people with business skills to make it available to use of the people, it's a whole big process and some inefficiencies that come in at certain locations. Cause that low percent of tech transfer.

Mit Micro-Electro-Mechanical Systems (MEMS) zu Diagnose-Tools entwickeln

Biologie

Microfabrication of Chip-sized Scaffolds for Three-dimensional Cell cultivation

Using microfabrication technologies is a prerequisite to create scaffolds of reproducible geometry and constant quality for three-dimensional cell cultivation. These technologies offer a wide spectrum of advantages not only for manufacturing but also for different applications. The size and shape of formed cell clusters can be influenced by the exact and reproducible architecture of the microfabricated scaffold and, therefore, the diffusion path length of nutrients and gases can be controlled.1 This is unquestionably a useful tool to prevent apoptosis and necrosis of cells due to an insufficient nutrient and gas supply or removal of cellular metabolites.
Our polymer chip, called CellChip, has the outer dimensions of 2 x 2 cm with a central microstructured area. This area is subdivided into an array of up to 1156 microcontainers with a typical dimension of 300 m edge length for the cubic design (cp- or cf-chip) or of 300 m diameter and depth for the round design (r-chip).2
So far, hot embossing or micro injection moulding (in combination with subsequent laborious machining of the parts) was used for the fabrication of the microstructured chips. Basically, micro injection moulding is one of the only polymer based replication techniques that, up to now, is capable for mass production of polymer microstructures.3 However, both techniques have certain unwanted limitations due to the processing of a viscous polymer melt with the generation of very thin walls or integrated through holes. In case of the CellChip, thin bottom layers are necessary to perforate the polymer and provide small pores of defined size to supply cells with culture medium e.g. by microfluidic perfusion of the containers.
In order to overcome these limitations and to reduce the manufacturing costs we have developed a new microtechnical approach on the basis of a down-scaled thermoforming process. For the manufacturing of highly porous and thin walled polymer chips, we use a combination of heavy ion irradiation, microthermoforming and track etching. In this so called "SMART" process (Substrate Modification And Replication by Thermoforming) thin polymer films are irradiated with energetic heavy projectiles of several hundred MeV introducing so-called "latent tracks" Subsequently, the film in a rubber elastic state is formed into three dimensional parts without modifying or annealing the tracks. After the forming process, selective chemical etching finally converts the tracks into cylindrical pores of adjustable diameter.

We present two processes for the microfabrication of porous polymer chips for three-dimensional cell cultivation. The first one is hot embossing combined with a solvent vapour welding process. The second one uses a recently developed microthermoforming process combined with ion track technology leading to a significant simplification of manufacture.

Microfabrication der Chip-Größe Gerüste für die dreidimensionale Kultivierung der Zellen

Using microfabrication technologies is a prerequisite to create scaffolds of reproducible geometry and constant quality for three-dimensional cell ...

Compact Lens-less Digital Holographic Microscope for MEMS Inspection and Characterization

A micro-electro-mechanical-system (MEMS) is a widely used component in many industries, including energy, biotechnology, medical, communications, and automotive. However, effective inspection and characterization metrology systems are needed to ensure the functional reliability of MEMS. This study presents a system based on digital holography as a tool for MEMS metrology. Digital holography has gained increasing attention in the past 20 years. With the fast development and decreasing cost of sensor arrays, resolution of such systems has increased broadening potential applications. Thus, it has attracted attention from both research and industry sides as a potential reliable tool for industrial metrology. Indeed, by recording the interference pattern between an object beam (which contains sample height information) and a reference beam on a CCD camera, one can retrieve the quantitative phase information of an object. However, most of digital holographic systems are bulky and thus not easy to implement on industry production lines. The novelty of the system presented is that it is lens-less and thus very compact. In this study, it is shown that the Compact Digital Holographic Microscope (CDHM) can be used to evaluate several characteristics typically consider as criteria in MEMS inspections. The surface profiles of MEMS in both static and dynamic conditions are presented. Comparison with AFM is investigated to validate the accuracy of the CDHM.

We present a compact reflection digital holographic system (CDHM) for inspection and characterization of MEMS devices. A lens-less design using a diverging input wave providing natural geometrical magnification is demonstrated. Both static and dynamic studies are presented.

Compact-Objektiv lose digitale holografische Mikroskop für MEMS-Inspektion und Charakterisierung

A micro-electro-mechanical-system (MEMS) is a widely used component in many industries, including energy, biotechnology, medical, communications, and ...

Fabrication of Carbon-Based Ionic Electromechanically Active Soft Actuators

Ionic electromechanically active capacitive laminates are a type of smart material that move in response to electrical stimulation. Due to the soft, compliant and biomimetic nature of this deformation, actuators made of the laminate have received increasing interest in soft robotics and (bio)medical applications. However, methods to easily fabricate the active material in large (even industrial) quantities and with a high batch-to-batch and within-batch repeatability are needed to transfer the knowledge from laboratory to industry. This protocol describes a simple, industrially scalable and reproducible method for the fabrication of ionic carbon-based electromechanically active capacitive laminates and the preparation of actuators made thereof. The inclusion of a passive and chemically inert (insoluble) middle layer (e.g., a textile-reinforced polymer network or microporous Teflon) distinguishes the method from others. The protocol is divided into five steps: membrane preparation, electrode preparation, current collector attachment, cutting and shaping, and actuation. Following the protocol results in an active material that can, for example, compliantly grasp and hold a randomly shaped object as demonstrated in the article.

This article describes a fast and simple manufacturing process of ionic electromechanically active composite materials for actuators in biomedical, biomimetic and soft robotics applications. The key fabrication steps, their importance for the actuators&#39; final properties, and some of the main characterization techniques are described in detail.

Herstellung von kohlenstoffbasierten ionischen Elektromechanischen Soft Actuatoren

Ionic electromechanically active capacitive laminates are a type of smart material that move in response to electrical stimulation. Due to the soft, ...

Fabrication of Micro-Patterned Chip with Controlled Thickness for High-Throughput Cryogenic Electron Microscopy

A major limitation for the efficient and high-throughput structure analysis of biomolecules using cryogenic electron microscopy (cryo-EM) is the difficulty of preparing cryo-EM samples with controlled ice thickness at the nanoscale. The silicon (Si)-based chip, which has a regular array of micro-holes with graphene oxide (GO) window patterned on a thickness-controlled silicon nitride (SixNy) film, has been developed by applying microelectromechanical system (MEMS) techniques. UV photolithography, chemical vapor deposition, wet and dry etching of the thin film, and drop-casting of 2D nanosheet materials were used for mass-production of the micro-patterned chips with GO windows. The depth of the micro-holes is regulated to control the ice thickness on-demand, depending on the size of the specimen for cryo-EM analysis. The favorable affinity of GO toward biomolecules concentrates the biomolecules of interest within the micro-hole during cryo-EM sample preparation. The micro-patterned chip with GO windows enables high-throughput cryo-EM imaging of various biological molecules, as well as inorganic nanomaterials.

A newly developed micro-patterned chip with graphene oxide windows is fabricated by applying microelectromechanical system techniques, enabling efficient and high-throughput cryogenic electron microscopy imaging of various biomolecules and nanomaterials.

Herstellung eines mikrostrukturierten Chips mit kontrollierter Dicke für die kryogene Elektronenmikroskopie mit hohem Durchsatz

A major limitation for the efficient and high-throughput structure analysis of biomolecules using cryogenic electron microscopy (cryo-EM) is the ...

An Additive Manufacturing Technique for the Facile and Rapid Fabrication of Hydrogel-based Micromachines with Magnetically Responsive Components

Polyethylene glycol (PEG)-based hydrogels are biocompatible hydrogels that have been approved for use in humans by the FDA. Typical PEG-based hydrogels have simple monolithic architectures and often function as scaffolding materials for tissue engineering applications. More sophisticated structures typically take a long time to fabricate and do not contain moving components. This protocol describes a photolithography method that allows for facile and rapid microfabrication of PEG structures and devices. This strategy involves an in-house developed fabrication stage that allows for the rapid fabrication of 3D structures by building upwards in a layer-by-layer fashion. Independent moving components can also be aligned and assembled onto support structures to form integrated devices. These independent components are doped with superparamagnetic iron oxide nanoparticles that are sensitive to magnetic actuation. In this manner, the fabricated devices can be actuated using external magnets to yield movement of the components within. Hence, this technique allows for the fabrication of sophisticated MEMS-like devices (micromachines) that are composed entirely out of a biocompatible hydrogel, able to function without an onboard power source, and respond to a contact-less method of actuation. This manuscript describes the fabrication of both the fabrication set-up as well as the step-by-step method for the microfabrication of these hydrogels-based MEMS-like devices.

An additive manufacturing strategy for processing UV-crosslinkable hydrogels has been developed. This strategy allows for the layer-by-layer assembly of microfabricated hydrogel structures as well as the assembly of independent components, yielding integrated devices containing moving components that are responsive to magnetic actuation.

Zusatzstoff Herstellungstechnik für die einfache und schnelle Herstellung von Hydrogel-basierte Micromachines mit magnetisch reagieren Komponenten

Polyethylene glycol (PEG)-based hydrogels are biocompatible hydrogels that have been approved for use in humans by the FDA. Typical PEG-based hydrogels ...

Fabrication of a Multiplexed Artificial Cellular MicroEnvironment Array

Cellular microenvironments consist of a variety of cues, such as growth factors, extracellular matrices, and intercellular interactions. These cues are well orchestrated and are crucial in regulating cell functions in a living system. Although a number of researchers have attempted to investigate the correlation between environmental factors and desired cellular functions, much remains unknown. This is largely due to the lack of a proper methodology to mimic such environmental cues in vitro, and simultaneously test different environmental cues on cells. Here, we report an integrated platform of microfluidic channels and a nanofiber array, followed by high-content single-cell analysis, to examine stem cell phenotypes altered by distinct environmental factors. To demonstrate the application of this platform, this study focuses on the phenotypes of self-renewing human pluripotent stem cells (hPSCs). Here, we present the preparation procedures for a nanofiber array and the microfluidic structure in the fabrication of a Multiplexed Artificial Cellular MicroEnvironment (MACME) array. Moreover, overall steps of the single-cell profiling, cell staining with multiple fluorescent markers, multiple fluorescence imaging, and statistical analyses, are described.

This article describes the detailed methodology to prepare a Multiplexed Artificial Cellular MicroEnvironment (MACME) array for high-throughput manipulation of physical and chemical cues mimicking in vivo cellular microenvironments and to identify the optimal cellular environment for human pluripotent stem cells (hPSCs) with single-cell profiling.

Herstellung eines Multiplex künstliche zellulären Mikroumgebung Arrays

Cellular microenvironments consist of a variety of cues, such as growth factors, extracellular matrices, and intercellular interactions. These cues are ...