Name: using adhesive patterning to construct 3d paper microfluidic devices
Uploaded: 2016-04-01T14:00:00.000+00:00
Duration: 7 min 53 s
Description: Watch this Scientific Journal Video about Using Adhesive Patterning to Construct 3D Paper Microfluidic Devices at JoVE.com

Questo lavoro è sostenuto da un fondo da Bourns College of Engineering della University of California, Riverside. BK ha ricevuto una borsa di studio dal polmone-Wen Tsai Memorial Award nella progettazione meccanica.

1. Planar dispositivo 4-layer (strati sovrapposti) Costruzione <ol><li> Matrici di stampa di ogni strato del dispositivo 9 su ogni pezzo di carta da filtro con una stampante a inchiostro solido. 11,12 collocare ogni carta filtro su una piastra riscaldante a 170 ° C per 2 min. Questo si scioglierà l&#39;inchiostro a base di cera e farlo penetrare completamente lo spessore della carta, formando barriere idrofobi. NOTA: I disegni precisi utilizzati sono disponibili come file supplementari. </li><li> Rimuovere la carta filtro dalla piastra e lasciarlo raffreddare a temperatura ambiente. </li><li> Deposito 4 ml di 5 dye mm (rosso: rosso allura; giallo: tartrazina; blu: sale disodico erioglaucine; verde: 10: 1 mix di tartrazina: erioglaucine sale disodico) in ciascun ramo (un colore per ramo) di livello 3 (terzo strato dalla parte superiore del dispositivo completato) utilizzando una micropipetta. </li><li> Inizia con il livello più in basso. Fissare la carta da filtro tra la sagoma e un supporto rigido, ad esempio un pezzo di vetro piatto, utilizzando clip legantes, o un altro metodo temporaneo simile. Assicurarsi che lo stencil è piatta contro la carta. Questo ridurrà al minimo eventuali ombre proiettate da spruzzo lo stencil sulla carta. </li><li> Applicare l&#39;adesivo (vedi elenco dei materiali e delle attrezzature), con un secondo di circa 1,33 (un quattro-count a 180 bpm) a spruzzo da circa 24 cm. 9,10 Durante questo tempo, spostare la lattina di adesivo attraverso lo stencil a un ritmo medio. Troppo lento della corsa attraverso la matrice causerà adesivo ad accumularsi sulla stencil stesso, intasamento. Troppo rapida della corsa non riuscirà a depositare adesiva sufficiente sulla carta. Quattro passaggi in questo periodo (su-giù-su-giù) sono sufficienti a prevenire le ombre a spruzzo. </li><li> Rimuovere stencil e posizionare il successivo strato del dispositivo (strati numerati sono disponibili come file supplementari) sopra allo strato appena spruzzato, allineando i bordi della carta. Premere con forza i due strati insieme. </li><li> Sostituire stencil e ripetere il processo di spruzzatura per ogni strato del dispositivo. Rimuovere la STAck di dispositivi e luogo di imballaggio nastro attraverso lo strato inferiore. Questo impedisce qualsiasi perdita di fluido dal dispositivo. Tagliare singoli dispositivi dal foglio con le forbici, seguendo il bordo della regione stampata. </li></ol> 2. Planar dispositivo a 4 strati (Layer Origami piegato) Costruzione <ol><li> fogli di stampa che contengono tutti gli strati del dispositivo su carta da filtro utilizzando una stampante a inchiostro solido. Posizionare la carta filtro su una piastra riscaldante a 170 ° C per 2 min. Rimuovere la carta filtro dalla piastra e lasciarlo raffreddare a temperatura ambiente. NOTA: I disegni precisi utilizzati sono disponibili come file supplementari. </li><li> Deposito 4 ml di 5 dye mm (rosso: rosso allura; giallo: tartrazina; blu: sale disodico erioglaucine; verde: 10: 1 mix di tartrazina: erioglaucine sale disodico) in ciascun ramo (un colore per ramo) di livello 3 (terzo strato dalla parte superiore del dispositivo completata) via micropipetta. </li><li> Bloccare il foglio di dispositivi tra la sagoma e un supporto rigido, ad esempio un pezzo di vetro piatto, Utilizzando binderclips, o un altro metodo temporaneo simile. Assicurarsi che lo stencil è piatta contro la carta. </li><li> Applicare l&#39;adesivo (vedi elenco dei materiali e delle attrezzature), con un secondo di circa 1,33 (un quattro-count a 180 bpm) a spruzzo da circa 24 cm. Quattro passaggi in questo periodo (su-giù-su-giù) sono sufficienti a prevenire le ombre a spruzzo. </li><li> Rimuovere stencil e girare il foglio. Sostituire stencil e spruzzare retro della carta. Rimuovere il foglio di dispositivi e iniziare pieghevole in una piega fisarmonica, come illustrato in Figura 1. Tagliare ogni dispositivo dal foglio con le forbici, seguendo il bordo della regione stampata. Posizionare il nastro di imballaggio attraverso lo strato inferiore. </li></ol> 3. non planare (Origami) costruzione dispositivo <ol><li> Dispositivo di stampa (Figura 2A) su carta da filtro utilizzando una stampante inchiostro solido e posizionare la carta da filtro su una piastra calda a 170 ° C per 2 min. Rimuovere dispositivo dalla piastra e lasciarlo raffreddare a temperatura ambiente. NOTA:I disegni precisi utilizzati sono disponibili come file supplementari. </li><li> Stampa piega pattern (Figura 2C) su carta stampante utilizzando una stampante inchiostro solido e tagliati nelle dimensioni della carta da filtro. Posizionare modello piega su una piastra riscaldante a 170 ° C per 2 min, per fondere la cera, causando il modello per essere visibili da entrambi i lati del foglio. Rimuovere modello piega dalla piastra e lasciarlo raffreddare a temperatura ambiente. </li><li> Allineare i bordi del modello piega ai bordi della carta contenente i modelli di canale e collegare i due pezzi di carta utilizzando clip legante, o un altro metodo temporaneo simile. </li><li> Tracciare il modello piega con una punta smussata, applicando abbastanza forza che sono segni sul foglio di dispositivo, ma non è così difficile che la carta modello piega strappa. In tal caso, il dispositivo rischia di essere danneggiato. Precreasing provoca la carta da piegare molto più facilmente e permette una maggiore accuratezza e precisione in piega. </li><li> Iniziare piegare il dispositivo con la montagna e vallepieghe secondo il modello piega. Una volta che l&#39;adesivo è stato applicato, l&#39;intero dispositivo deve essere montato molto rapidamente, quindi piegando il dispositivo il più possibile prima dell&#39;applicazione dell&#39;adesivo è molto utile. </li><li> Una volta che il dispositivo è ripiegato, aprire il dispositivo per esporre le porzioni del dispositivo che richiedono adesivo. Tagliare maschere (Figura 2D) che limitano dove sull&#39;adesivo dispositivo può essere applicato, con una lama di rasoio. </li><li> Bloccare il dispositivo tra la sagoma e maschera e un supporto rigido, ad esempio un pezzo di vetro piatto. Assicurarsi che lo stencil è piatto contro il dispositivo. Applicare l&#39;adesivo (vedi materiali e delle attrezzature della lista) con un secondo di circa 1,33 (un quattro-count a 180 bpm) a spruzzo da circa 24 cm. Quattro passaggi in questo periodo (su-giù-su-giù) sono sufficienti a prevenire le ombre a spruzzo. Rimuovere stencil e girare il foglio. Sostituire stencil e maschera e spruzzare retro della carta. </li><li> Rimuovere immediatamente dispositivo da stencil e iniziare a piegare ladispositivo. Una volta che il dispositivo è completamente ripiegato, applicare pressione alla porzione adesivo contenente fino l&#39;adesivo si è asciugato. NOTA: Il tempo di asciugatura del collante è molto sensibile all&#39;umidità ambientale, così in ambienti con bassa umidità, pieghevoli in una camera controllata umidità permette più tempo per piegare il dispositivo. </li></ol> 4. Wicking di prova per dispositivi 4-layer <ol><li> Casualmente selezionare 20 dispositivi, precedentemente montati secondo i protocolli di cui sopra. dispositivi Mettere in un luogo al riparo da qualsiasi vento o brezze per ridurre al minimo l&#39;evaporazione. Cassetta 40 microlitri di acqua in ingresso di ciascun dispositivo. Registrare il tempo impiegato da ciascun dispositivo di avere tutti i suoi punti completamente riempito con la tintura. </li></ol> 5. Origami Wicking Confronto <ol><li> Costruire due pavoni Origami - uno secondo il protocollo sopra (punto 3), e l&#39;altro senza l&#39;uso di uno stampino durante l&#39;applicazione dell&#39;adesivo. </li><li> Inserire un&#39;estremità di un piccolo pAPER piombo (circa 5 mm di larghezza di 5 cm di lunghezza) nel corpo di ogni pavone. </li><li> Posizionare entrambi pavoni in una camera mantenuta ad un&#39;umidità relativa elevata (&gt; 90%) per ridurre al minimo l&#39;evaporazione. Mettere ogni gamba e piombo di ogni pavone in un contenitore riempito con 5 mM di colorante (rosso: rosso allura, giallo: tartrazina, blu: erioglaucine sale disodico). Record processo traspirante con una fotocamera digitale. </li></ol>

<ol>
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I protocolli di cui sopra utilizzano lamiere forate come stampini per l&#39;applicazione di adesivi aerosol per la costruzione di planare e dispositivi microfluidici carta 3D non planari. Nei dispositivi planari, questo ha il vantaggio di dispositivi che consentano di essere completamente dispiegata dopo che l&#39;adesivo si è asciugato senza distruggere il dispositivo. In altre tecniche di costruzione adesivi a base, questo è quasi impossibile, anche se, alcuni disegni permettono parziale smontaggio distruttivo stacc...

Negli ultimi anni, la carta microfluidica ha raccolto una notevole popolarità per il suo potenziale per fornire point a basso costo delle cure (POC) dispositivi diagnostici. 1-3 dispositivi POC offrono funzionalità simili a quelle dei test di laboratorio, con sede in un formato che permette risulta essere ottenuto in tempi relativamente brevi. dispositivi POC in carta sono a basso costo, leggero e alternative facili da usare per costosi chip di microfluidica e laboratori miniaturizzati, che li rende ideali per l&#39;utilizzo in ambienti con risorse limitate. I dispositivi microfluidici carta più comuni sono dispositivi di flusso laterali monodimensionali, ma planare tridimensionale (3D) di carta dispositivi microfluidici tengono promettono di fornire dispositivi diagnostici multiplex 4 che occupano un ingombro molto più piccolo di quello richiesto da un dispositivo 2D 5 e corrispondentemente utilizzare un volume campione più piccolo. Inizialmente, carta 3D planare dispositivi microfluidici stati assemblati, layer-by-layer wiesimo modellato strati di carta si alternano con il laser-cut nastro biadesivo. Fori allineati accuratamente tagliato nello strato di nastro erano pieni di polvere di cellulosa per garantire inter-strato di trasporto di liquidi. 4 Un certo numero di metodi alternativi sono stati ulteriormente sviluppati, 6-9 ciascuno migliorando diversi aspetti dei dispositivi. In particolare, evitando adesivi, i dispositivi potrebbero essere piegati tramite tecniche origami con strati tenuti insieme da un morsetto esterno. 8 Questo elimina qualsiasi interferenza potenziale adesivo in un test diagnostico e permette al dispositivo di essere dispiegata post-utilizzo, potenzialmente permettendo campione ancora più piccolo volumi di visualizzazione dei risultati internamente. In alternativa, utilizzando un adesivo aerosol applicata tra ogni strato di carta, fogli di dispositivi possono essere montati simultaneamente, senza tempo patterning e l&#39;allineamento del nastro. 9 Tuttavia, applicando un adesivo aerosol attraverso uno stencil, è possibile ottenere il vantaggio dientrambe queste tecniche. Spruzzando l&#39;adesivo attraverso uno stampino, solo una frazione di adesivo viene applicato al dispositivo, riducendo al minimo possibili interferenze con il trasferimento di fluidi interstrato. Inoltre, con la selezione attenta stampino, un modello di adesivo può essere applicato che si traduce in incollaggio semi-permanente, consentendo dispositivi di essere spiegati dopo l&#39;uso, pur fornendo sufficienti contatti interstrato per consentire il fluido per favorire tra gli strati. Infine, applicando adesivi aerosol attraverso uno stampino facilita la costruzione di dispositivi microfluidici carta 3D non planari, minimizzando la quantità di adesivo applicato alle facce adiacenti che possono richiedere piegatura frequente e svolgimento durante la costruzione. 10 Inoltre, l&#39;uso di adesivo modellato permette dispositivo per essere spiegato dopo l&#39;uso per lo stoccaggio più conveniente. dispositivi microfluidici carta non planare 3D dovrebbero essere utilizzati per compiti che altrimenti sarebbero impossibili in un Devic planare 3De. La figura 1 illustra il flusso del processo generale utilizzato per costruire sia dispositivi 3D non planari planare e.

<table><tbody><tr><td>Camera</td><td>Nikon</td><td>D5100</td><td></td></tr><tr><td>Solid-ink printer</td><td>Xerox</td><td>ColorQube 8880</td><td></td></tr><tr><td>Hotplate</td><td>Torrey Pines</td><td>HS60</td><td></td></tr><tr><td>Humidity chamber</td><td>Electro-Tech Systems</td><td>5503-E</td><td></td></tr><tr><td>Spray adhesive</td><td>3M</td><td>62497749309</td><td>Super 77 (16.75 oz can)</td></tr><tr><td>Filter paper</td><td>Whatman</td><td>Grade 4</td><td></td></tr><tr><td>Perforated steel sheet</td><td>MetalsDepot</td><td>PS16116</td><td></td></tr><tr><td>Tartrazine</td><td>Sigma-Aldritch</td><td>T0388</td><td></td></tr><tr><td>Allura Red</td><td>Sigma-Aldritch</td><td>458848</td><td></td></tr><tr><td>Erioglaucine disodium salt</td><td>Sigma-Aldritch</td><td>861146</td><td></td></tr></tbody></table>

using adhesive patterning to construct 3d paper microfluidic devices

We demonstrate the use of patterned aerosol adhesives to construct both planar and nonplanar 3D paper microfluidic devices. By spraying an aerosol adhesive through a metal stencil, the overall amount of adhesive used in assembling paper microfluidic devices can be significantly reduced. We show on a simple 4-layer planar paper microfluidic device that the optimal adhesive application technique and device construction style depends heavily on desired performance characteristics. By moderately increasing the overall area of a device, it is possible to dramatically decrease the wicking time and increase device success rates while also reducing the amount of adhesive required to keep the device together. Such adhesive application also causes the adhesive to form semi-permanent bonds instead of permanent bonds between paper layers, enabling single-use devices to be non-destructively disassembled after use. Nonplanar 3D origami devices also benefit from the semi-permanent bonds during folding, as it reduces the likelihood that unrelated faces may accidently stick together. Like planar devices, nonplanar structures see reduced wicking times with patterned adhesive application vs uniformly applied adhesive.

I test del dispositivo 4 strati sono stati eseguiti in una camera sigillata, proteggendoli da qualsiasi vento o brezza che potrebbe causare eccessiva evaporazione del volume del fluido depositato limitato. La maggior parte del assorbimento nei dispositivi 4-layer è negli strati intermedi del dispositivo, per cui le differenze di traspirazione velocità a causa dell&#39;evaporazione avrebbero dovuto essere minimo. Inoltre, vi è l&#39;assorbimento laterale minimo, con soli 13 mm tra l&#3...

Watch this Scientific Journal Video about Using Adhesive Patterning to Construct 3D Paper Microfluidic Devices at JoVE.com

Using Adhesive Patterning to Construct 3D Paper Microfluidic Devices

Dimostriamo l&#39;uso di adesivi aerosol fantasia per costruire dispositivi microfluidici carta 3D. Questo metodo di moduli di domanda adesivi obbligazioni semi-permanenti tra gli strati, consentendo dispositivi monouso di essere non distruttiva smontato dopo l&#39;uso e per facilitare le strutture non planari pieghevole complesse.

Utilizzando adesivo Patterning per costruire dispositivi microfluidici di carta 3D

We demonstrate the use of patterned aerosol adhesives to construct both planar and nonplanar 3D paper microfluidic devices. By spraying an aerosol ...

using-adhesive-patterning-to-construct-3d-paper-microfluidic-devices

Research

JoVE Journal

Bioengineering

7.5K Views.  University of California, Riverside.  Dimostriamo l'uso di adesivi aerosol fantasia per costruire dispositivi microfluidici carta 3D. Questo metodo di moduli di domanda adesivi obbligazioni semi-permanenti tra gli strati, consentendo dispositivi monouso di essere non distruttiva smontato dopo l'uso e per facilitare le strutture non planari pieghevole complesse. 

Video: Using Adhesive Patterning to Construct 3D Paper Microfluidic Devices

Origami Inspired Self-assembly of Patterned and Reconfigurable Particles

There are numerous techniques such as photolithography, electron-beam lithography and soft-lithography that can be used to precisely pattern two dimensional (2D) structures. These technologies are mature, offer high precision and many of them can be implemented in a high-throughput manner. We leverage the advantages of planar lithography and combine them with self-folding methods1-20 wherein physical forces derived from surface tension or residual stress, are used to curve or fold planar structures into three dimensional (3D) structures. In doing so, we make it possible to mass produce precisely patterned static and reconfigurable particles that are challenging to synthesize.
In this paper, we detail visualized experimental protocols to create patterned particles, notably, (a) permanently bonded, hollow, polyhedra that self-assemble and self-seal due to the minimization of surface energy of liquefied hinges21-23 and (b) grippers that self-fold due to residual stress powered hinges24,25. The specific protocol described can be used to create particles with overall sizes ranging from the micrometer to the centimeter length scales. Further, arbitrary patterns can be defined on the surfaces of the particles of importance in colloidal science, electronics, optics and medicine. More generally, the concept of self-assembling mechanically rigid particles with self-sealing hinges is applicable, with some process modifications, to the creation of particles at even smaller, 100 nm length scales22, 26 and with a range of materials including metals21, semiconductors9 and polymers27. With respect to residual stress powered actuation of reconfigurable grasping devices, our specific protocol utilizes chromium hinges of relevance to devices with sizes ranging from 100 &mu;m to 2.5 mm. However, more generally, the concept of such tether-free residual stress powered actuation can be used with alternate high-stress materials such as heteroepitaxially deposited semiconductor films5,7 to possibly create even smaller nanoscale grasping devices.

We describe experimental details of the synthesis of patterned and reconfigurable particles from two dimensional (2D) precursors. This methodology can be used to create particles in a variety of shapes including polyhedra and grasping devices at length scales ranging from the micro to centimeter scale.

Origami Ispirato auto-assemblaggio di particelle Fantasia e riconfigurabile

There are numerous techniques such as photolithography, electron-beam lithography and soft-lithography that can be used to precisely pattern two ...

Ricerca

Chimica

Creating Adhesive and Soluble Gradients for Imaging Cell Migration with Fluorescence Microscopy

Cells can sense and migrate towards higher concentrations of adhesive cues such as the glycoproteins of the extracellular matrix and soluble cues such as growth factors. Here, we outline a method to create opposing gradients of adhesive and soluble cues in a microfluidic chamber, which is compatible with live cell imaging. A copolymer of poly-L-lysine and polyethylene glycol (PLL-PEG) is employed to passivate glass coverslips and prevent non-specific adsorption of biomolecules and cells. Next, microcontact printing or dip pen lithography are used to create tracks of streptavidin on the passivated surfaces to serve as anchoring points for the biotinylated peptide arginine-glycine-aspartic acid (RGD) as the adhesive cue. A microfluidic device is placed onto the modified surface and used to create the gradient of adhesive cues (100% RGD to 0% RGD) on the streptavidin tracks. Finally, the same microfluidic device is used to create a gradient of a chemoattractant such as fetal bovine serum (FBS), as the soluble cue in the opposite direction of the gradient of adhesive cues.

A method for the assembly of adhesive and soluble gradients in a microscopy chamber for live cell migration studies is described. The engineered environment combines antifouling surfaces and adhesive tracks with solution gradients and therefore allows one to determine the relative importance of guidance cues.

Creazione di sfumature adesivi e solubile per la migrazione di imaging cellulare con microscopia a fluorescenza

Cells can sense and migrate towards higher concentrations of adhesive cues such as the glycoproteins of the extracellular matrix and soluble cues such as ...

Bioingegneria

Cell Patterning on Photolithographically Defined 
Parylene-C: SiO2 Substrates

Cell patterning platforms support broad research goals, such as construction of predefined in vitro neuronal networks and the exploration of certain central aspects of cellular physiology. To easily combine cell patterning with Multi-Electrode Arrays (MEAs) and silicon-based &#8216;lab on a chip&#8217; technologies, a microfabrication-compatible protocol is required. We describe a method that utilizes deposition of the polymer parylene-C on SiO2&#160;wafers. Photolithography enables accurate and reliable patterning of parylene-C at micron-level resolution. Subsequent activation by immersion in fetal bovine serum (or another specific activation solution) results in a substrate in which cultured cells adhere to, or are repulsed by, parylene or SiO2 regions respectively. This technique has allowed patterning of a broad range of cell types (including primary murine hippocampal cells, HEK 293 cell line, human neuron-like teratocarcinoma cell line, primary murine cerebellar granule cells, and primary human glioma-derived stem-like cells). Interestingly, however, the platform is not universal; reflecting the importance of cell-specific adhesion molecules. This cell patterning process is cost effective, reliable, and importantly can be incorporated into standard microfabrication (chip manufacturing) protocols, paving the way for integration of microelectronic technology.

Cell Patterning on Photolithographically Defined 
Parylene-C: SiO2 Substrates

This protocol describes a microfabrication-compatible method for cell patterning on SiO2. A predefined parylene-C design is photolithographically printed on SiO2 wafers. Following incubation with serum (or other activation solution) cells adhere specifically to (and grow according to the conformity of) underlying parylene-C, whilst being repulsed by SiO2 regions.

Patterning cellulare su fotolitograficamente Definito parylene-C: SiO<sub&gt; 2</sub&gt; Substrati

Cell patterning platforms support broad research goals, such as construction of predefined in vitro neuronal networks and the exploration of certain ...

Microfluidic Genipin Deposition Technique for Extended Culture of Micropatterned Vascular Muscular Thin Films

The chronic nature of vascular disease progression requires the development of experimental techniques that simulate physiologic and pathologic vascular behaviors on disease-relevant time scales. Previously, microcontact printing has been used to fabricate two-dimensional functional arterial mimics through patterning of extracellular matrix protein as guidance cues for tissue organization. Vascular muscular thin films utilized these mimics to assess functional contractility. However, the microcontact printing fabrication technique used typically incorporates hydrophobic PDMS substrates. As the tissue turns over the underlying extracellular matrix, new proteins must undergo a conformational change or denaturing in order to expose hydrophobic amino acid residues to the hydrophobic PDMS surfaces for attachment, resulting in altered matrix protein bioactivity, delamination, and death of the tissues.
Here, we present a microfluidic deposition technique for patterning of the crosslinker compound genipin. Genipin serves as an intermediary between patterned tissues and PDMS substrates, allowing cells to deposit newly-synthesized extracellular matrix protein onto a more hydrophilic surface and remain attached to the PDMS substrates. We also show that extracellular matrix proteins can be patterned directly onto deposited genipin, allowing dictation of engineered tissue structure. Tissues fabricated with this technique show high fidelity in both structural alignment and contractile function of vascular smooth muscle tissue in a vascular muscular thin film model. This technique can be extended using other cell types and provides the framework for future study of chronic tissue- and organ-level functionality.

We present a method for microfluidic deposition of patterned genipin and fibronectin on PDMS substrates, allowing extended viability of vascular smooth muscle cell-dense tissues. This tissue fabrication method is combined with previous vascular muscular thin film technology to measure vascular contractility over disease-relevant time courses.

Microfluidic genipina Deposizione Tecnica per la cultura estesa di micropatterned vascolari muscolari Thin Films

The chronic nature of vascular disease progression requires the development of experimental techniques that simulate physiologic and pathologic vascular ...

Construction of Modular Hydrogel Sheets for Micropatterned Macro-scaled 3D Cellular Architecture

Hydrogels can be patterned at the micro-scale using microfluidic or micropatterning technologies to provide an in vivo-like three-dimensional (3D) tissue geometry. The resulting 3D hydrogel-based cellular constructs have been introduced as an alternative to animal experiments for advanced biological studies, pharmacological assays and organ transplant applications. Although hydrogel-based particles and fibers can be easily fabricated, it is difficult to manipulate them for tissue reconstruction. In this video, we describe a fabrication method for micropatterned alginate hydrogel sheets, together with their assembly to form a macro-scale 3D cell culture system with a controlled cellular microenvironment. Using a mist form of the calcium gelling agent, thin hydrogel sheets are easily generated with a thickness in the range of 100 - 200 &#181;m, and with precise micropatterns. Cells can then be cultured with the geometric guidance of the hydrogel sheets in freestanding conditions. Furthermore, the hydrogel sheets can be readily manipulated using a micropipette with an end-cut tip, and can be assembled into multi-layered structures by stacking them using a patterned polydimethylsiloxane (PDMS) frame. These modular hydrogel sheets, which can be fabricated using a facile process, have potential applications of in vitro drug assays and biological studies, including functional studies of micro- and macrostructure and tissue reconstruction.

We describe the fabrication of micropatterned hydrogel sheets using a simple process, which can be assembled and manipulated in a freestanding form. Using these modular hydrogel sheets, a simple macro-scaled 3D cell culture system can be generated with a controlled cellular microenvironment.

Costruzione di fogli modulare idrogel per micropatterned macro-scala 3D Cellular Architettura

Hydrogels can be patterned at the micro-scale using microfluidic or micropatterning technologies to provide an in vivo-like three-dimensional (3D) tissue ...

Micropatterning and Assembly of 3D Microvessels

In vitro platforms to study endothelial cells and vascular biology are largely limited to 2D endothelial cell culture, flow chambers with polymer or glass based substrates, and hydrogel-based tube formation assays. These assays, while informative, do not recapitulate lumen geometry, proper extracellular matrix, and multi-cellular proximity, which play key roles in modulating vascular function. This manuscript describes an injection molding method to generate engineered vessels with diameters on the order of 100 &#181;m. Microvessels are fabricated by seeding endothelial cells in a microfluidic channel embedded within a native type I collagen hydrogel. By incorporating parenchymal cells within the collagen matrix prior to channel formation, specific tissue microenvironments can be modeled and studied. Additional modulations of hydrodynamic properties and media composition allow for control of complex vascular function within the desired microenvironment. This platform allows for the study of perivascular cell recruitment, blood-endothelium interactions, flow response, and tissue-microvascular interactions. Engineered microvessels offer the ability to isolate the influence from individual components of a vascular niche and precisely control its chemical, mechanical, and biological properties to study vascular biology in both health and disease.

This manuscript presents an injection molding method to engineer microvessels that recapitulate physiological properties of endothelium. The microfluidic-based process creates patent 3D vascular networks with tailorable conditions, such as flow, cellular composition, geometry, and biochemical gradients. The fabrication process and examples of potential applications are described.

Micropatterning e montaggio dei microvasi 3D

In vitro platforms to study endothelial cells and vascular biology are largely limited to 2D endothelial cell culture, flow chambers with polymer or glass ...

Patterning of Microorganisms and Microparticles through Sequential Capillarity-assisted Assembly

Controlled patterning of microorganisms into defined spatial arrangements offers unique possibilities for a broad range of biological applications, including studies of microbial physiology and interactions. At the simplest level, accurate spatial patterning of microorganisms would enable reliable, long-term imaging of large numbers of individual cells and transform the ability to quantitatively study distance-dependent microbe-microbe interactions. More uniquely, coupling accurate spatial patterning and full control over environmental conditions, as offered by microfluidic technology, would provide a powerful and versatile platform for single-cell studies in microbial ecology. 
This paper presents a microfluidic platform to produce versatile and user-defined patterns of microorganisms within a microfluidic channel, allowing complete optical access for long-term, high-throughput monitoring. This new microfluidic technology is based on capillarity-assisted particle assembly and exploits the capillary forces arising from the controlled motion of an evaporating suspension inside a microfluidic channel to deposit individual microsized objects in an array of traps microfabricated onto a polydimethylsiloxane (PDMS) substrate. Sequential depositions generate the desired spatial layout of single or multiple types of micro-sized objects, dictated solely by the geometry of the traps and the filling sequence. 
The platform has been calibrated using colloidal particles of different dimensions and materials: it has proven to be a powerful tool to generate diverse colloidal patterns and perform surface functionalization of trapped particles. Furthermore, the platform was tested on microbial cells, using Escherichia coli cells as a model bacterium. Thousands of individual cells were patterned on the surface, and their growth was monitored over time. In this platform, the coupling of single-cell deposition and microfluidic technology allows both geometric patterning of microorganisms and precise control of environmental conditions. It thus opens a window into the physiology of single microbes and the ecology of microbe-microbe interactions, as shown by preliminary experiments.

We present a technology that uses capillarity-assisted assembly in a microfluidic platform to pattern micro-sized objects suspended in a liquid, such as bacteria and colloids, into prescribed arrays on a polydimethylsiloxane substrate.

Modellazione di microrganismi e microparticelle attraverso l'assemblaggio sequenziale assistito da capillarità

Controlled patterning of microorganisms into defined spatial arrangements offers unique possibilities for a broad range of biological applications, ...

Ingegneria

Fabrication of Three-dimensional Paper-based Microfluidic Devices for Immunoassays

Paper wicks fluids autonomously due to capillary action. By patterning paper with hydrophobic barriers, the transport of fluids can be controlled and directed within a layer of paper. Moreover, stacking multiple layers of patterned paper creates sophisticated three-dimensional microfluidic networks that can support the development of analytical and bioanalytical assays. Paper-based microfluidic devices are inexpensive, portable, easy to use, and require no external equipment to operate. As a result, they hold great promise as a platform for point-of-care diagnostics. In order to properly evaluate the utility and analytical performance of paper-based devices, suitable methods must be developed to ensure their manufacture is reproducible and at a scale that is appropriate for laboratory settings. In this manuscript, a method to fabricate a general device architecture that can be used for paper-based immunoassays is described. We use a form of additive manufacturing (multi-layer lamination) to prepare devices that comprise multiple layers of patterned paper and patterned adhesive. In addition to demonstrating the proper use of these three-dimensional paper-based microfluidic devices with an immunoassay for human chorionic gonadotropin (hCG), errors in the manufacturing process that may result in device failures are discussed. We expect this approach to manufacturing paper-based devices will find broad utility in the development of analytical applications designed specifically for limited-resource settings.

We detail a method to fabricate three-dimensional paper-based microfluidic devices for use in the development of immunoassays. Our approach to device assembly is a type of multilayer, additive manufacturing. We demonstrate a sandwich immunoassay to provide representative results for these types of paper-based devices.

Fabbricazione di dispositivi microfluidici basati su carta tridimensionale per gli immunodosaggi

Paper wicks fluids autonomously due to capillary action. By patterning paper with hydrophobic barriers, the transport of fluids can be controlled and ...

A Versatile Method of Patterning Proteins and Cells

Substrate and cell patterning techniques are widely used in cell biology to study cell-to-cell and cell-to-substrate interactions. Conventional patterning techniques work well only with simple shapes, small areas and selected bio-materials. This article describes a method to distribute cell suspensions as well as substrate solutions into complex, long, closed (dead-end) polydimethylsiloxane (PDMS) microchannels using negative pressure. This method enables researchers to pattern multiple substrates including fibronectin, collagen, antibodies (Sal-1), poly-D-lysine (PDL), and laminin. Patterning of substrates allows one to indirectly pattern a variety of cells. We have tested C2C12 myoblasts, the PC12 neuronal cell line, embryonic rat cortical neurons, and amphibian retinal neurons. In addition, we demonstrate that this technique can directly pattern fibroblasts in microfluidic channels via brief application of a low vacuum on cell suspensions. The low vacuum does not significantly decrease cell viability as shown by cell viability assays. Modifications are discussed for application of the method to different cell and substrate types. This technique allows researchers to pattern cells and proteins in specific patterns without the need for exotic materials or equipment and can be done in any laboratory with a vacuum.

This report describes a simple, easy to perform technique, using low pressure vacuum, to fill microfluidic channels with cells and substrates for biological research.

Un metodo versatile di patterning proteine ​​e cellule

Substrate and cell patterning techniques are widely used in cell biology to study cell-to-cell and cell-to-substrate interactions. Conventional patterning ...

Fabbricazione micro-goffrata di dispositivi analitici basati su carta di nanocellulosa  

Microembossing: A Convenient Process for Fabricating Microchannels on Nanocellulose Paper-Based Microfluidics

Nanopaper, derived from nanofibrillated cellulose, has generated considerable interest as a promising material for microfluidic applications. Its appeal lies in a range of excellent&#160;qualities, including an exceptionally smooth surface, outstanding optical transparency, a uniform nanofiber matrix with nanoscale porosity, and customizable chemical properties. Despite the rapid growth of nanopaper-based microfluidics, the current techniques used to create microchannels on nanopaper, such as 3D printing, spray coating, or manual cutting and assembly, which are crucial for practical applications, still possess certain limitations, notably susceptibility to contamination. Furthermore, these methods are restricted to the production of millimeter-sized channels. This study introduces a straightforward process that utilizes convenient plastic micro-molds for simple microembossing operations to fabricate microchannels on nanopaper, achieving a minimum width of 200 &#181;m. The developed microchannel outperforms existing approaches, achieving a fourfold improvement, and can be fabricated within 45 min. Furthermore, fabrication parameters have been optimized, and a convenient quick-reference table is provided for application developers. The proof-of-concept for a laminar mixer, droplet generator, and functional nanopaper-based analytical devices (NanoPADs) designed for Rhodamine B sensing using surface-enhanced Raman spectroscopy was demonstrated. Notably, the NanoPADs exhibited exceptional performance with improved limits of detection. These outstanding results can be attributed to the superior optical properties of nanopaper and the recently developed accurate microembossing method, enabling the integration and fine-tuning of the NanoPADs.

Autore in primo piano: Rivoluzionare la microfluidica attraverso la fabbricazione di microcanali su nanocarta 

This protocol describes a straightforward process that utilizes convenient plastic micro-molds for simple microembossing operations to fabricate microchannels on nanofibrillated cellulose paper, achieving a minimum width of 200 &#181;m.

Microgoffratura: un processo conveniente per la fabbricazione di microcanali su microfluidica a base di carta nanocellulosica

Nanopaper, derived from nanofibrillated cellulose, has generated considerable interest as a promising material for microfluidic applications. Its appeal ...

Utilizzando adesivo Patterning per costruire dispositivi microfluidici di carta 3D

Riepilogo

Esplora Altri Video

Capitoli in questo video

Origami Ispirato auto-assemblaggio di particelle Fantasia e riconfigurabile

Creazione di sfumature adesivi e solubile per la migrazione di imaging cellulare con microscopia a fluorescenza

Patterning cellulare su fotolitograficamente Definito parylene-C: SiO

Microfluidic genipina Deposizione Tecnica per la cultura estesa di micropatterned vascolari muscolari Thin Films

Costruzione di fogli modulare idrogel per micropatterned macro-scala 3D Cellular Architettura

Micropatterning e montaggio dei microvasi 3D

Modellazione di microrganismi e microparticelle attraverso l'assemblaggio sequenziale assistito da capillarità

Fabbricazione di dispositivi microfluidici basati su carta tridimensionale per gli immunodosaggi

Un metodo versatile di patterning proteine e cellule

Microgoffratura: un processo conveniente per la fabbricazione di microcanali su microfluidica a base di carta nanocellulosica

Utilizzando adesivo Patterning per costruire dispositivi microfluidici di carta 3D

Riepilogo

Esplora Altri Video

Capitoli in questo video

Origami Ispirato auto-assemblaggio di particelle Fantasia e riconfigurabile

Creazione di sfumature adesivi e solubile per la migrazione di imaging cellulare con microscopia a fluorescenza

Patterning cellulare su fotolitograficamente Definito parylene-C: SiO

Microfluidic genipina Deposizione Tecnica per la cultura estesa di micropatterned vascolari muscolari Thin Films

Costruzione di fogli modulare idrogel per micropatterned macro-scala 3D Cellular Architettura

Micropatterning e montaggio dei microvasi 3D

Modellazione di microrganismi e microparticelle attraverso l'assemblaggio sequenziale assistito da capillarità

Fabbricazione di dispositivi microfluidici basati su carta tridimensionale per gli immunodosaggi

Un metodo versatile di patterning proteine ​​e cellule

Microgoffratura: un processo conveniente per la fabbricazione di microcanali su microfluidica a base di carta nanocellulosica

Un metodo versatile di patterning proteine e cellule