Name: stereolithographic 3d printing with renewable acrylates
Uploaded: 2018-09-12T15:00:00.000+00:00
Duration: 8 min 28 s
Description: Watch this Scientific Journal Video about Stereolithographic 3D Printing with Renewable Acrylates at JoVE.com

Questo studio è stato sostenuto dal centro di applicazione del polimero GreenPAC come parte del progetto 140413: "stampa 3D in produzione". Vorremmo riconoscere Albert Hartman, Corinne van Noordenne, Rens van Leeuwen, Anniek Bruins, Femke Tamminga, Jur van Dijken e Albert Woortman per facilitare le riprese video.

Attenzione: Si prega di consultare tutte le schede di dati di sicurezza (MSDS) prima dell'uso.
1. preparazione della resina fotocurabili
Nota: Si prega di utilizzare dispositivi di protezione individuale (occhiali di sicurezza, guanti, camice da laboratorio) durante la procedura seguente. Vedi il nostro precedente lavoro12 per maggiori dettagli su questa sezione.
<ol><li>Versare 50 g di 1,10-decanediol Diacrilato (SA5201) in una beuta da 500 mL.</li>
	<li>Aggiungere 1,0 g di diphenyl(2,4,6-trimethylbenzoyl) fosfinossido (TPO) e 0,40 g di 2,5 -bis(5 -tert-butil-benzoxazol-2-yl) tiofene (BBOT) al pallone.</li>
	<li>Dotare la beuta con un agitatore meccanico e agitare la miscela a 200 rpm per 5 min a temperatura ambiente per sciogliere TPO e BBOT nel monomero acrilato.</li>
	<li>Aggiungere 100 g di pentaeritritolo tetracrilato e 100 g di acrilato a resina epossidica multifunzionale (Vedi Tabella materiali) alla miscela.</li>
	<li>Mescolare il composto a 200 rpm per 30 min a 50 ° C per garantire una resina omogenea.</li>
	<li>Rimuovere l'agitatore meccanico e montare il recipiente con un tappo. Il pallone è avvolto in un foglio di alluminio per proteggere la resina fotopolimerica acrilato di biobased (BAPR) dalla luce. Nota: Il protocollo può essere messo in pausa qui.</li>
	<li>Coprire la piastra inferiore di un reometro con geometria di piatti paralleli con il photoresin.</li>
	<li>Impostare la distanza tra le piastre a 1 mm e coprire il reometro con un cappuccio resistente alle raggi UV.</li>
	<li>Misurare la viscosità della resina a temperatura ambiente a tassi del taglio da 0,1 a 100 s-1; ad esempio,0.100, 0.126, 0,158, 0,200, 0.251, 0.316, 0.398, 0,501, 0.631, 0.794, 1.00, 1.26, 1.58, 2.00, 2,51, 3.16, 3,98, 5.01, 6,31, 7,94, 10.0, 12,6, 15,8, 20.0, 25,1, 31,6, 39,8, 50,1, 63,1, 79,4 e 100 s-1.</li>
</ol>2. Stereolithographic stampa 3D con Biobased acrilati
Nota: Vedere il nostro precedente lavoro12 per maggiori dettagli su questa sezione.
<ol><li>Accendere la stampante 3D di SLA e selezionare la modalità di apertura.</li>
	<li>Avviare il software di preparazione del modello in un computer. Scegliere impostazioni di stampa desiderato: materiale (trasparente), versione (V4) e spessore dello strato (50 µm).</li>
	<li>Aprire il modello digitale del prototipo di forma complessa, un file di lingua (STL) standard a mosaico (vedere File di codifica supplementare) e scegliere la posizione e l'orientamento sulla piattaforma di compilazione.  Caricare il processo di stampa dal software di preparazione del modello per la stampante 3D di SLA. Nota: A seconda dell'architettura del prodotto, una struttura di sostegno può essere integrata nel modello 3D per stabilizzare il costrutto durante la fabbricazione. In caso il prototipo di forma complessa dimostrato qui, una struttura di supporto non è necessaria se stampato normale alla direzione di compilazione.</li>
	<li>Versare 200 mL del photoresin biobased in un serbatoio di resina. Aprire la stampante 3D e montare correttamente il serbatoio di resina.</li>
	<li>Montare la piattaforma di compilazione e chiudere la stampante 3D.</li>
	<li>Avviare il processo di stampa.</li>
	<li>Attendere che la stampante 3D fabbricare prototipi a forma complesse.  Non aprire la stampante fino a quando il processo di stampa è terminato. Nota: Prima di stampare, assicurarsi che la stampante 3D è livellata. Per il protocollo ha dimostrato, la lunghezza d'onda del laser UV è 405 nm. La data di stampa dell'oggetto è 2,5 h.</li>
</ol>3. post-trattamento del 3D stampato oggetti
Nota: Si prega di utilizzare dispositivi di protezione individuale (occhiali di sicurezza, guanti) durante la procedura seguente.
<ol><li>Al termine il processo di stampa, aprire la stampante. Rimuovere la piattaforma di compilazione, con pezzi prodotti collegati e chiudere la stampante.</li>
	<li>Aprire la stazione di lavaggio, riempita con alcool isopropilico e inserire la piattaforma di compilazione. Avviare la procedura e risciacquo per 20 min rimuovere qualsiasi resina non reagito.</li>
	<li>Una volta ultimata la procedura di risciacquo, rimuovere la piattaforma di compilazione dalla stazione di lavaggio e scollegare i prototipi dalla piattaforma di compilazione.</li>
	<li>I prototipi per aria, lasciare asciugare per 30 min. Nel frattempo, preriscaldare il forno UV a 60 ° C. Nota: Preriscaldamento richiederà almeno 15 min. La lunghezza d'onda UV del forno è 405 nm, identica alla lunghezza d'onda del laser di SLA.</li>
	<li>Aprire il forno UV e posizionare rapidamente i prototipi sulla piattaforma rotante. Chiudere il forno UV e cura per 60 min a 60 ° C per garantire la completa conversione.</li>
	<li>Una volta ultimata la procedura di post-vulcanizzazione, aprire il forno UV e prendere dei prototipi.</li>
</ol>4. caratterizzazione della morfologia superficiale dei prototipi di forma complessa
Nota: Vedere il nostro precedente lavoro12 per maggiori dettagli su questa sezione.
<ol><li>Taglio ca. 1 cm dell'elica interna dal prototipo a forma complesso utilizzando una lama di rasoio.</li>
	<li>Fissare il campione per il portacampioni con nastro conduttivo double sided carbonio.</li>
	<li>Prima di formazione immagine, rivestire il campione con 30 nm Pt/Pd (80: 20) su un sistema di sputtering.</li>
	<li>Inserire il campione in un microscopio elettronico a scansione a una tensione di accelerazione di 5 kV. Acquisire diverse immagini del campione a 30x e 120 ingrandimenti.</li>
</ol>

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	<li>Van Wijk, A., van Wijk, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> 3D Printing with Biomaterials: Towards a Sustainable and Circular Economy. , (2015).</li><li>Gross, B. C., Erkal, J. L., Lockwood, S. Y., Chen, C., Spence, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+3D+Printing+and+Its+Potential+Impact+on+Biotechnology+and+the+Chemical+Sciences.">Evaluation of 3D Printing and Its Potential Impact on Biotechnology and the Chemical Sciences.</a> Analytical Chemistry. 86, 3240-3253 (2014).</li><li>Chia, H. N., Wu, B. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+advances+in+3D+printing+of+biomaterials.">Recent advances in 3D printing of biomaterials.</a> Journal of Biological Engineering. 9, 4 (2015).</li><li>Mechels, F. P. W., Feijen, J., Grijpma, D. W. <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+on+stereolithography+and+its+applications+in+biomedical+engineering.">A review on stereolithography and its applications in biomedical engineering.</a> Biomaterials. 31, 6121-6130 (2010).</li><li>Skoog, S. A., Goering, P. L., Narayan, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stereolithography+in+tissue+engineering.">Stereolithography in tissue engineering.</a> Journal of Materials Science: Materials in Medicine. 25, 845-856 (2014).</li><li>Bhatia, S. K., Ramadurai, K. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> 3D Printing and Bio-Based Materials in Global Health. , (2017).</li><li>Oskui, S. M., Diamante, G., Liao, C., Shi, W., Gan, J., Schlenk, D., Grover, W. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessing+and+Reducing+the+Toxicity+of+3D-Printed+Parts.">Assessing and Reducing the Toxicity of 3D-Printed Parts.</a> Environmental Science &amp; Technology Letters. 3, 1-6 (2016).</li><li>Gong, H., Beauchamp, M., Perry, S., Woolley, A. T., Nordin, G. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optical+approach+to+resin+formulation+for+3D+printed+microfluidics.">Optical approach to resin formulation for 3D printed microfluidics.</a> RSC Advances. 5, 106621-106632 (2015).</li><li>Zarek, M., Layani, M., Cooperstein, I., Sachyani, E., Cohn, D., Magdassi, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=3D+printing+of+shape+memory+polymers+for+flexible+electronic+devices.">3D printing of shape memory polymers for flexible electronic devices.</a> Advanced Materials. 28, 4449-4454 (2016).</li><li>Ligon-Auer, S. C., Schwentenwein, M., Gorsche, C., Stampfl, J., Liska, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toughening+of+photo-curable+polymer+networks:+A+review.">Toughening of photo-curable polymer networks: A review.</a> Polymer Chemistry. 7, 257-286 (2016).</li><li>Miao, S., Zhu, W., Castro, N. J., Nowicki, M., Zhou, X., Cui, H., Fisher, J. P., Zhang, L. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=4D+printing+smart+biomedical+scaffolds+with+novel+soybean+oil+epoxidized+acrylate.">4D printing smart biomedical scaffolds with novel soybean oil epoxidized acrylate.</a> Scientific Reports. 6, 27226 (2016).</li><li>Voet, V. S. D., Strating, T., Schnelting, G. H. M., Dijkstra, P., Tietema, M., Xu, J., Woortman, A. J. J., Loos, K., Jager, J., Folkersma, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biobased+acrylate+photocurable+resin+formulation+for+stereolithographic+3D+printing.">Biobased acrylate photocurable resin formulation for stereolithographic 3D printing.</a> ACS Omega. 3, 1403-1408 (2018).</li><li>Ligon-Auer, S. C., Liska, R., Stampfl, J., Gurr, M., M&#252;lhaupt, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polymers+for+3D+Printing+and+Customized+Additive+Manufacturing.">Polymers for 3D Printing and Customized Additive Manufacturing.</a> Chemical Reviews. 117, 10212-10290 (2017).</li><li>Weng, Z., Zhou, Y., Lin, W., Senthil, T., Wu, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structure-property+relationship+of+nano+enhanced+stereolithography+resin+for+desktop+SLA+3D+printer.">Structure-property relationship of nano enhanced stereolithography resin for desktop SLA 3D printer.</a> Composites: Part A. 88, 234-242 (2016).</li><li>Scalera, F., Esposito Corcione, C., Montagna, F., Sannino, A., Maffezzoli, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+and+characterization+of+UV+curable+epoxy/hydroxyapatite+suspensions+for+stereolithography+applied+to+bone+tissue+engineering.">Development and characterization of UV curable epoxy/hydroxyapatite suspensions for stereolithography applied to bone tissue engineering.</a> Ceramics International. 40, 15455-15462 (2014).</li><li>Lee, H., Fang, N. 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Produzione additiva viene applicato nella fabbricazione di prototipi su misura e piccole serie, quando i più alti costi di produzione per pezzo possono competere con i processi convenzionali, poiché non vi è alcuna necessità di produzione di stampi e utensili. Nell'ultimo decennio, i ricavi da servizi e prodotti legati alla produzione di additivi sono cresciuti esponenzialmente13. La frazione più grande di vendita di materiale è da fotopolimeri. La crescita ha attirato l'attenzione e ha avvi...

Prototipazione rapida consente libertà di progettazione e produzione su richiesta e che la produzione efficiente di 3D costruisce in un modo a strati1. Di conseguenza, stampa 3D come una tecnica di fabbricazione è sviluppato rapidamente in anni recenti2. Varie tecnologie sono disponibili, tutti basandosi sulla traduzione di modelli virtuali in oggetti fisici e l'applicazione di processi come estrusione, deposizione di energia diretta, solidificazione di polvere, foglio di laminazione e fotopolimerizzazione. Quest'ultima coinvolge graduale indurimento UV delle resine in fotopolimero liquido. Nel 1986, scafo e colleghi di lavoro sviluppato apparato di stereolitografia (SLA), una stampante 3D basati su laser UV. Più recentemente, un processo simile chiamato digital light processing (DLP) è diventato disponibile, in cui fotopolimerizzazione è iniziata da un proiettore. Insieme, DLP e SLA vengono denominati per stereolitografia 3D stampa3.
SLA viene applicato in alta risoluzione prototipazione e realizzazione di dispositivi biomedicali4,5. Questa tecnologia è superiore all'ampiamente usata deposizione fusa modellazione (FDM) in termini di precisione, finitura superficiale e risoluzione6. A seconda dell'architettura del prodotto, una struttura di supporto è integrata nel modello 3D per stabilizzare il costrutto durante la fabbricazione. Inoltre, un trattamento post-stampa dei pezzi prodotti è richiesto7,8. In genere, oggetti stampati vengono lavati in un bagno di alcool per sciogliere la resina non reagita, e successiva polimerizzazione in forno UV viene eseguita per garantire piena conversione della polimerizzazione9.
In generale, resine per la produzione additiva basati su Litografia si affidano fotocurabili sistemi contenenti multifunzionale acrilati o epossidi10. Le resine fotopolimeriche attuale sul mercato commerciale sono basata sui combustibili fossili e costosi, mentre la disponibilità di basso costo rinnovabili resine è necessario per facilitare la produzione locale e senza sprechi di prodotti sostenibili 3D per un biobased economia1 , 6. recentemente, resine fotopolimeriche basate su rinnovabili acrilati erano sviluppate e applicate con successo in stereolitografia 3D stampa11,12. In questo protocollo dettagliato, dimostriamo la prototipazione rapida con resine biobased su un apparato commerciale stereolitografia. Particolare attenzione è rivolta ai passaggi critici della procedura, cioè, resina formulazione e post-stampa trattamenti, per aiutare gli operatori di nuovi nel campo della produzione additiva.

<table><tbody><tr><td>Isobornyl acrylate&amp;nbsp;</td><td>Sartomer</td><td>SA5102</td><td>Acrylate monomer</td></tr><tr><td>1,10-decanediol diacrylate</td><td>Sartomer</td><td>SA5201</td><td>Acrylate monomer</td></tr><tr><td>Pentaerythritol tetraacrylate</td><td>Sartomer</td><td>SA5400</td><td>Acrylate monomer</td></tr><tr><td>Multifunctional epoxy acrylate</td><td>Sartomer</td><td>SA7101</td><td>Acrylate oligomer</td></tr><tr><td>Diphenyl(2,4,6-trimethylbenzoyl) phosphine oxide (TPO), 97%</td><td>Sigma Aldrich</td><td>415952</td><td>Photoinitiator</td></tr><tr><td>2,5-bis(5-&lt;em&gt;tert&lt;/em&gt;-butyl-benzoxazol-2-yl)thiophene (BBOT), 99%</td><td>Sigma Aldrich</td><td>223999</td><td>Optical absorber</td></tr><tr><td>Isopropyl alcohol (IPA), 99%</td><td>Bleko</td><td>1010500</td><td>For alcohol bath (applied in Form Wash)</td></tr><tr><td>Paar Physica MCR300&amp;nbsp;</td><td>Anton Paar</td><td>-</td><td>Rheometer with parallel plate geometry</td></tr><tr><td>Form 2 Printer</td><td>Formlabs</td><td>-</td><td>Desktop SLA 3D printer</td></tr><tr><td>Form Wash&amp;nbsp;</td><td>Formlabs</td><td>-</td><td>Washing station</td></tr><tr><td>Form Cure</td><td>Formlabs</td><td>-</td><td>UV oven</td></tr><tr><td>Instron 4301 1KN Series IX</td><td>Instron</td><td>-</td><td>Universal testing machine</td></tr><tr><td>Philips XL30 ESEM-FEG&amp;nbsp;</td><td>Philips</td><td>-</td><td>Scanning electron microscope</td></tr></tbody></table>

stereolithographic 3d printing with renewable acrylates

L'accessibilità di costi competitivi materiali rinnovabili e la loro applicazione nella produzione di additivi è essenziale per un'economia efficiente biobased. Dimostriamo la prototipazione rapida di resine sostenibile utilizzando una stampante 3D di stereolithographic. Formulazione della resina avviene mediante semplice miscela di biobased acrilato monomeri e oligomeri con un photoinitiatior e assorbitore di ottico. Viscosità della resina è controllata dal monomero rapporto oligomero e viene determinato in funzione della velocità di taglio di un reometro con geometria parallela del piatto. Un apparato di stereolithographic addebitato con le resine biobased è impiegato per produrre prototipi a forma complessi con elevata precisione. I prodotti richiedono un post-trattamento, tra cui alcol risciacquo e irradiazione UV, per garantire una polimerizzazione completa. La caratteristica alta risoluzione e superficie eccellente finitura dei prototipi è rivelato da microscopia elettronica a scansione.

Quattro composizioni di resina rappresentante vengono visualizzati in tabella 1, insieme al loro contenuto di carbonio biobased medio (BC) derivato dal AC individuale dei componenti. La viscosità della resina (Figura 1) è influenzata dal rapporto di acrilato monomeri e oligomeri e in genere viene illustrato comportamento newtoniano. Le proprietà meccaniche di parti prodotte da varie resine sono state determinate mediante analisi di solleci...

Watch this Scientific Journal Video about Stereolithographic 3D Printing with Renewable Acrylates at JoVE.com

Stereolithographic 3D Printing with Renewable Acrylates

Un protocollo per la produzione additiva con resine fotopolimeriche rinnovabili su un apparato di stereolitografia è presentato.

Stereolithographic stampa 3D con rinnovabili acrilati

The accessibility of cost-competitive renewable materials and their application in additive manufacturing is essential for an efficient biobased economy. ...

stereolithographic-3d-printing-with-renewable-acrylates

Research

JoVE Journal

Chemistry

9.4K Views.  NHL Stenden University of Applied Sciences. Un protocollo per la produzione additiva con resine fotopolimeriche rinnovabili su un apparato di stereolitografia è presentato.

Video: Stereolithographic 3D Printing with Renewable Acrylates

Planar and Three-Dimensional Printing of Conductive Inks

Printed electronics rely on low-cost, large-area fabrication routes to create flexible or multidimensional electronic, optoelectronic, and biomedical devices1-3. In this paper, we focus on one- (1D), two- (2D), and three-dimensional (3D) printing of conductive metallic inks in the form of flexible, stretchable, and spanning microelectrodes.
Direct-write assembly4,5 is a 1-to-3D printing technique that enables the fabrication of features ranging from simple lines to complex structures by the deposition of concentrated inks through fine nozzles (~0.1 - 250 &mu;m). This printing method consists of a computer-controlled 3-axis translation stage, an ink reservoir and nozzle, and 10x telescopic lens for visualization. Unlike inkjet printing, a droplet-based process, direct-write assembly involves the extrusion of ink filaments either in- or out-of-plane. The printed filaments typically conform to the nozzle size. Hence, microscale features (&lt; 1 &mu;m) can be patterned and assembled into larger arrays and multidimensional architectures.
In this paper, we first synthesize a highly concentrated silver nanoparticle ink for planar and 3D printing via direct-write assembly. Next, a standard protocol for printing microelectrodes in multidimensional motifs is demonstrated. Finally, applications of printed microelectrodes for electrically small antennas, solar cells, and light-emitting diodes are highlighted.

Planar and three-dimensional printing of conductive metallic inks is described. Our approach provides new avenues for fabricating printed electronic, optoelectronic, and biomedical devices in unusual layouts at the microscale.

Stampa planare e tridimensionale di inchiostri conduttivi

Printed electronics rely on low-cost, large-area fabrication routes to create flexible or multidimensional electronic, optoelectronic, and biomedical ...

Ricerca

Bioingegneria

3D Printing of Biomolecular Models for Research and Pedagogy

The construction of physical three-dimensional (3D) models of biomolecules can uniquely contribute to the study of the structure-function relationship. 3D structures are most often perceived using the two-dimensional and exclusively visual medium of the computer screen. Converting digital 3D molecular data into real objects enables information to be perceived through an expanded range of human senses, including direct stereoscopic vision, touch, and interaction. Such tangible models facilitate new insights, enable hypothesis testing, and serve as psychological or sensory anchors for conceptual information about the functions of biomolecules. Recent advances in consumer 3D printing technology enable, for the first time, the cost-effective fabrication of high-quality and scientifically accurate models of biomolecules in a variety of molecular representations. However, the optimization of the virtual model and its printing parameters is difficult and time consuming without detailed guidance. Here, we provide a guide on the digital design and physical fabrication of biomolecule models for research and pedagogy using open source or low-cost software and low-cost 3D printers that use fused filament fabrication technology.

Physical models of biomolecules can facilitate an understanding of their structure-function for the researcher, aid in communication between researchers, and serve as an educational tool in pedagogical endeavors. Here, we provide detailed guidance for the 3D printing of accurate models of biomolecules using fused filament fabrication desktop 3D printers.

La stampa 3D dei modelli biomolecolari per la Ricerca e Pedagogia

The construction of physical three-dimensional (3D) models of biomolecules can uniquely contribute to the study of the structure-function relationship. 3D ...

Ingegneria

Printing Thermoresponsive Reverse Molds for the Creation of Patterned Two-component Hydrogels for 3D Cell Culture

Bioprinting is an emerging technology that has its origins in the rapid prototyping industry. The different printing processes can be divided into contact bioprinting1-4 (extrusion, dip pen and soft lithography), contactless bioprinting5-7 (laser forward transfer, ink-jet deposition) and laser based techniques such as two photon photopolymerization8. It can be used for many applications such as tissue engineering9-13, biosensor microfabrication14-16 and as a tool to answer basic biological questions such as influences of co-culturing of different cell types17. Unlike common photolithographic or soft-lithographic methods, extrusion bioprinting has the advantage that it does not require a separate mask or stamp. Using CAD software, the design of the structure can quickly be changed and adjusted according to the requirements of the operator. This makes bioprinting more flexible than lithography-based approaches.
Here we demonstrate the printing of a sacrificial mold to create a multi-material 3D structure using an array of pillars within a hydrogel as an example. These pillars could represent hollow structures for a vascular network or the tubes within a nerve guide conduit. The material chosen for the sacrificial mold was poloxamer 407, a thermoresponsive polymer with excellent printing properties which is liquid at 4 &deg;C and a solid above its gelation temperature ~20 &deg;C for 24.5% w/v solutions18. This property allows the poloxamer-based sacrificial mold to be eluted on demand and has advantages over the slow dissolution of a solid material especially for narrow geometries. Poloxamer was printed on microscope glass slides to create the sacrificial mold. Agarose was pipetted into the mold and cooled until gelation. After elution of the poloxamer in ice cold water, the voids in the agarose mold were filled with alginate methacrylate spiked with FITC labeled fibrinogen. The filled voids were then cross-linked with UV and the construct was imaged with an epi-fluorescence microscope.

A bioprinter was used to create patterned hydrogels based on a sacrificial mold. The poloxamer mold was backfilled with a second hydrogel and then eluted, leaving voids which were filled with a third hydrogel. This method uses fast elution and good printability of poloxamer to generate complex architectures from biopolymers.

La stampa termosensibile Stampi inversa per la Creazione di Patterned idrogeli a due componenti per coltura cellulare 3D

Bioprinting is an emerging technology that has its origins in the rapid prototyping industry. The different printing processes can be divided into contact ...

Immunologia e infezioni

Procedure for the Transfer of Polymer Films Onto Porous Substrates with Minimized Defects

The fabrication of devices containing thin film composite membranes necessitates the transfer of these films onto the surfaces of arbitrary support substrates. Accomplishing this transfer in a highly controlled, mechanized, and reproducible manner can eliminate the creation of macroscale defect structures (e.g., tears, cracks, and wrinkles) within the thin film that compromise device performance and the usable area per sample. Here, we describe a general protocol for the highly controlled and mechanized transfer of a polymeric thin film onto an arbitrary porous support substrate for eventual use as a water filtration membrane device. Specifically, we fabricate a block copolymer (BCP) thin film on top of a sacrificial, water-soluble poly(acrylic acid) (PAA) layer and silicon wafer substrate. We then utilize a custom-designed, 3D-printed transfer tool and drain chamber system to deposit, lift-off, and transfer the BCP thin film onto the center of a porous anodized aluminum oxide (AAO) support disc. The transferred BCP thin film is shown to be consistently placed onto the center of the support surface due to the guidance of the meniscus formed between the water and the 3D-printed plastic drain chamber. We also compare our mechanized transfer-processed thin films to those that have been transferred by hand with the use of tweezers. Optical inspection and image analysis of the transferred thin films from the mechanized process confirm that little-to-no macroscale inhomogeneities or plastic deformations are produced, as compared to the multitude of tears and wrinkles produced from manual transfer by hand. Our results suggest that the proposed strategy for thin film transfer can reduce defects when compared to other methods across many systems and applications.

We present a procedure for highly controlled and wrinkle-free transfer of block copolymer thin films onto porous support substrates using a 3D-printed drain chamber. The drain chamber design is of general relevance to all procedures involving transfer of macromolecular films onto porous substrates, which is normally done by hand in an irreproducible fashion.

Procedura per il trasferimento di pellicole polimeriche su substrati porous con difetti ridotti al minimo

The fabrication of devices containing thin film composite membranes necessitates the transfer of these films onto the surfaces of arbitrary support ...

Three-dimensional Biomimetic Technology: Novel Biorubber Creates Defined Micro- and Macro-scale Architectures in Collagen Hydrogels

Tissue scaffolds play a crucial role in the tissue regeneration process. The ideal scaffold must fulfill several requirements such as having proper composition, targeted modulus, and well-defined architectural features. Biomaterials that recapitulate the intrinsic architecture of in vivo tissue are vital for studying diseases as well as to facilitate the regeneration of lost and malformed soft tissue. A novel biofabrication technique was developed which combines state of the art imaging, three-dimensional (3D) printing, and selective enzymatic activity to create a new generation of biomaterials for research and clinical application. The developed material, Bovine Serum Albumin rubber, is reaction injected into a mold that upholds specific geometrical features. This sacrificial material allows the adequate transfer of architectural features to a natural scaffold material. The prototype consists of a 3D collagen scaffold with 4 and 3 mm channels that represent a branched architecture. This paper emphasizes the use of this biofabrication technique for the generation of natural constructs. This protocol utilizes a computer-aided software (CAD) to manufacture a solid mold which will be reaction injected with BSA rubber followed by the enzymatic digestion of the rubber, leaving its architectural features within the scaffold material.

An innovative biofabrication technique was developed to engineer three-dimensional constructs that resemble the architectural features, components, and mechanical properties of in vivo tissue. This technique features a newly developed sacrificial material, BSA rubber, which transfers detailed spatial features, reproducing the in vivo architectures of a wide variety of tissues.

Tridimensionale Tecnologia biomimetica: Novel Biorubber Consente di creare Definito micro e macro scala Architetture in collagene idrogel

Tissue scaffolds play a crucial role in the tissue regeneration process. The ideal scaffold must fulfill several requirements such as having proper ...

Multimodal 3D Printing of Phantoms to Simulate Biological Tissue

Biomedical optical imaging is playing an important role in diagnosis and treatment of various diseases. However, the accuracy and the reproducibility of an optical imaging device are greatly affected by the performance characteristics of its components, the test environment, and the operations. Therefore, it is necessary to calibrate these devices by traceable phantom standards. However, most of the currently available phantoms are homogeneous phantoms that cannot simulate multimodal and dynamic characteristics of biological tissue. Here, we show the fabrication of heterogeneous tissue-simulating phantoms using a production line integrating a spin coating module, a polyjet module, a fused deposition modeling (FDM) module, and an automatic control framework. The structural information and the optical parameters of a &#34;digital optical phantom&#34; are defined in a prototype file, imported to the production line, and fabricated layer-by-layer with sequential switch between different printing modalities. Technical capability of such a production line is exemplified by the automatic printing of skin-simulating phantoms that comprise the epidermis, dermis, subcutaneous tissue, and an embedded tumor.

Spin coating, polyjet printing, and fused deposition modeling are integrated to produce multilayered heterogeneous phantoms that simulate structural and functional properties of biological tissue.

Stampa 3D multimodale di fantasmi per simulare il tessuto biologico

Biomedical optical imaging is playing an important role in diagnosis and treatment of various diseases. However, the accuracy and the reproducibility of ...

Interactive Molecular Model Assembly with 3D Printing

With the growth in accessibility of 3D printing, there has been a growing application of and interest in additive manufacturing processes in chemical laboratories and chemical education. Building on the long and successful history of physical modeling of molecular systems, we present select models along with a protocol to facilitate 3D printing of molecular structures that are able to do more than represent shape and connectivity. Models assembled as described incorporate dynamic aspects and degrees of freedom into saturated hydrocarbon structures. As a representative example, cyclohexane was assembled from parts printed and finished using different thermoplastics, and the resulting models retain their functionality at a variety of scales. The resulting structures show configurational space accessibility consistent with calculations and literature, and versions of these structures can be used as aids to illustrate concepts that are difficult to convey in other ways. This exercise enables us to evaluate successful printing protocols, make practical recommendations for assembly, and outline design principles for physical modeling of molecular systems. The provided structures, procedures, and results provide a foundation for individual manufacture and exploration of molecular structure and dynamics with 3D printing.

Physical modeling of microscopic systems helps obtain insights that are difficult to gain by other means. To facilitate the construction of physical molecular models, we demonstrate how 3D printing can be used to assemble functional macroscopic models that capture qualities of molecular systems in a tactile way.

Assemblaggio del modello molecolare interattivo con stampa 3D

With the growth in accessibility of 3D printing, there has been a growing application of and interest in additive manufacturing processes in chemical ...

Chimica

3D Printing and In Situ Surface Modification via Type I Photoinitiated Reversible Addition-Fragmentation Chain Transfer Polymerization

3D printing provides facile access to geometrically complex materials. However, these materials have intrinsically linked bulk and interfacial properties dependent on the chemical composition of the resin. In the current work, 3D printed materials are post-functionalized using the 3D printer hardware via a secondary surface-initiated polymerization process, thus providing independent control over the bulk and interfacial material properties. This process begins with preparing liquid resins, which contain a monofunctional monomer, a crosslinking multifunctional monomer, a photochemically labile species that enables initiation of polymerization, and critically, a thiocarbonylthio compound which facilitates reversible addition-fragmentation chain transfer (RAFT) polymerization. The thiocarbonylthio compound, known commonly as a RAFT agent, mediates the chain growth polymerization process and provides polymeric materials with more homogeneous network structures. The liquid resin is cured in a layer-by-layer fashion using a commercially available digital light processing 3D printer to give three-dimensional materials having spatially controlled geometries. The initial resin is removed and replaced with a new mixture containing functional monomers and photoinitiating species. The 3D printed material is then exposed to light from the 3D printer in the presence of the new functional monomer mixture. This allows photoinduced surface-initiated polymerization to occur from the latent RAFT agent groups on the surface of the 3D printed material. Given the chemical flexibility of both resins, this process allows a wide range of 3D printed materials to be produced with tailorable bulk and interfacial properties.

3D Printing and In Situ Surface Modification via Type I Photoinitiated Reversible Addition-Fragmentation Chain Transfer Polymerization

The present protocol describes the digital light processing-based 3D printing of polymeric materials using type I photoinitiated reversible addition-fragmentation chain transfer polymerization and the subsequent in situ material post-functionalization via surface-mediated polymerization. Photoinduced 3D printing provides materials with independently tailored and spatially controlled bulk and interfacial properties.

Stampa 3D e modifica della superficie in situ tramite polimerizzazione della catena di trasferimento della catena di addizione-frammentazione reversibile di tipo I

3D printing provides facile access to geometrically complex materials. However, these materials have intrinsically linked bulk and interfacial properties ...

Novel Process for 3D Printing Decellularized Matrices

3D bioprinting aims to create custom scaffolds that are biologically active and accommodate the desired size and geometry. A thermoplastic backbone can provide mechanical stability similar to native tissue while biologic agents offer compositional cues to progenitor cells, leading to their migration, proliferation, and differentiation to reconstitute the original tissues/organs1,2. Unfortunately, many 3D printing compatible, bioresorbable polymers (such as polylactic acid, PLA) are printed at temperatures of 210 &#176;C or higher - temperatures that are detrimental to biologics. On the other hand, polycaprolactone (PCL), a different type of polyester, is a bioresorbable, 3D printable material that has a gentler printing temperature of 65 &#176;C. Therefore, it was hypothesized that decellularized extracellular matrix (DM) contained within a thermally protective PLA barrier could be printed within PCL filament and remain in its functional conformation. In this work, osteochondral repair was the application for which the hypothesis was tested. As such, porcine cartilage was decellularized and encapsulated in polylactic acid (PLA) microspheres which were then extruded with polycaprolactone (PCL) into filament to produce 3D constructs via fused deposition modeling. The constructs with or without the microspheres (PLA-DM/PCL and PCL(-), respectively) were evaluated for differences in surface features.

This protocol describes the production of polycaprolactone (PCL) filament with embedded polylactic acid (PLA) microspheres which contain decellularized matrices (DM) for 3D printing of structural tissue engineering constructs.

Processo innovativo per la stampa 3D Decellularized matrici

3D bioprinting aims to create custom scaffolds that are biologically active and accommodate the desired size and geometry. A thermoplastic backbone can ...

Idrogel biostampati fototunable per sondare le risposte cellulari all'irrigidimento della ECM

3D Bioprinting Phototunable Hydrogels to Study Fibroblast Activation

Phototunable hydrogels can transform spatially and temporally in response to light exposure. Incorporating these types of biomaterials in cell-culture platforms and dynamically triggering changes, such as increasing microenvironmental stiffness, enables researchers to model changes in the extracellular matrix (ECM) that occur during fibrotic disease progression. Herein, a method is presented for 3D bioprinting a phototunable hydrogel biomaterial capable of two sequential polymerization reactions within a gelatin support bath. The technique of Freeform Reversible Embedding of Suspended Hydrogels (FRESH) bioprinting was adapted by adjusting the pH of the support bath to facilitate a Michael addition reaction. First, the bioink containing poly(ethylene glycol)-alpha methacrylate (PEG&#945;MA) was reacted off-stoichiometry with a cell-degradable crosslinker to form soft hydrogels. These soft hydrogels were later exposed to photoinitator and light to induce the homopolymerization of unreacted groups and stiffen the hydrogel. This protocol covers hydrogel synthesis, 3D bioprinting, photostiffening, and endpoint characterizations to assess fibroblast activation within 3D structures. The method presented here enables researchers to 3D bioprint a variety of materials that undergo pH-catalyzed polymerization reactions and could be implemented to engineer various models of tissue homeostasis, disease, and repair.

Autore in primo piano: Comprendere le malattie polmonari croniche utilizzando idrogel fototunable stampati in 3D 

This article describes how to 3D bioprint phototunable hydrogels to study extracellular matrix stiffening and fibroblast activation.

Idrogel fotoregistrabili in bioprinting 3D per studiare l'attivazione dei fibroblasti

Phototunable hydrogels can transform spatially and temporally in response to light exposure. Incorporating these types of biomaterials in cell-culture ...