The authors thank Sungwon Lim for intellectual contributions to device and mold design as well as Jambu Jambulingam and Rebecca Grossman-Kahn for creating intravaginal silicone probes using this process. This work is supported by the Bill and Melinda Gates Foundation, the Vodafone Americas Foundation, and the FDA (2P50FD003793).

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F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanical,+microscopical+and+fire+retardant+studies+of+ABS+polymers.">Mechanical, microscopical and fire retardant studies of ABS polymers.</a> Polymer Degradation and Stability. 64, 449-455 (1999).</li><li>Cassidy, P. E., Mores, M., Kerwick, D. J., Koeck, D. J., Verschoor, K. L., White, D. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemical+Resistance+of+Geosynthetic+Materials.">Chemical Resistance of Geosynthetic Materials.</a> Geotextiles and Geomembranes. 11, 61-98 (1992).</li><li>Akay, M., Ozden, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+influence+of+residual+stresses+on+the+mechanical+and+thermal+properties+of+injection+moulded+ABS+copolymer.">The influence of residual stresses on the mechanical and thermal properties of injection moulded ABS copolymer.</a> Journal of Materials Science. 30 (13), (1995).</li></ol>

Keiner der Autoren haben keine finanziellen Interessen im Wettbewerb in Bezug auf die Arbeit in diesem Artikel beschrieben.

Von allen beschriebenen Schritte ist vorsichtig Formenbau die entscheidend für den Erfolg. Die Form-Master sollte wie ein fester Körper mit Außengeometrien gleich der letzte Gerät erstellt werden. Diese Geometrien angepasst werden sollten, um für jede Materialschwund aufgrund des gewählten Elastomer sowie 3D-Druckerauflösung und Toleranzen zu berücksichtigen. Platzierung der Formteilungslinien und Durchgangslöchern für Gewindestangen und Schrauben sind voneinander abhängig. Hinzufügen von Trennlinien wird di...

Flüssig-Spritzgießen (LIM) (auch als Reaktionsspritzguss bekannt) wird oft verwendet, um elastomere Geräte von duroplastischen Elastomeren herzustellen, aber hohe Werkzeug-und Gerätekosten erfordern viel Vorab-Investitionen ein. Darüber hinaus können LIM technisch anspruchsvollen und aufwendig zu implementieren in Fällen mit komplexer Geometrie und Anforderungen für die Überform sein. Als Ergebnis, ist es in der Regel unpraktisch, traditionelle LIM in Ultra-Low-Volumen oder mit Frühstadium Gerätedesigns, die oft entstehen iterative Revisionen zu verwenden. Die typische Vorgehensweise für das Spritzgießen elastomeren Materialien beinhaltet die Injektion flüssigen Monomeren bei Drücken um 150 psi in eine Form mit Spezialspritzgussmaschinen 2. Temperaturen und Drücke gesteuert werden, um eine laminare Strömung zu gewährleisten und verhindern, dass Luft in die Form 3 eingefangen. Rohstoffe sind typischerweise zweiteilige Härtungssysteme, wie Platin Heilung Silikon, tHut in getrennten Kammern und Temperatur gesteuert vor der Injektion gehalten. Die beiden Komponenten des Ausgangsmaterials in einem Hochdruck-Mischkammer zuführt, die anschließend in den Formhohlraum gepumpt. Das Härten wird durch die Gegenwart eines Katalysators sowie Temperaturen um 150-200 ° C 4 erreicht. Schimmelpilze sind in der Regel aus Stahl oder Aluminium, präzise Toleranzen bearbeitet, um eine gute Dichtung um 3,5 Abschied Kanten erstellen. Leider ist dieser Prozess in der Regel besser geeignet für größere Serienfertigung bei hohen Formwerkzeugkosten sowie der Forderung nach Facheinspritzung und Regelungstechnik. Für das Rapid Prototyping von Polyurethan (PU)-Teile, ist es möglich, Stereolithographie (SLA) zu verwenden, um eine Form Master erstellen und produzieren eine Silikonkautschukform 6,7. Jedoch ist diese Technik nicht geeignet für die Umspritzung da es schwierig ist, eine genaue Ausrichtung der übergeformten Komponenten zu erreichen, wie das Silikon durchentwerfen, nicht eine starre Struktur. Ferner Herstellung von Vorrichtungen mit komplexen Geometrien, wie Einstülpungen oder ausgehöhlten Abschnitte, schwierig oder unmöglich. Die Voraussetzung für komplexe oder präzise Formtrennlinien und starre dünne Elemente sind mehr als oft nicht, mit dem flüssigen Gummi Formprozess unvereinbar. Die oben genannten Produktionsmaßstab oder Spätstadium-Prototyping-Verfahren sind oft unpraktisch für Frühphasen-Entwicklung medizinischer Geräte, in denen ein paar Geräte müssen für Proof-of-Konzept-und Machbarkeitsstudien in der menschlichen hergestellt werden, wie es oft der Fall in akademischen Labor und Start-up-Unternehmens-Umgebungen. Der Mangel an Alternativen bedeutet oft, dass selbst im Frühstadium der Entwicklung würde hohe Kosten verursachen, die viele Geräteentwickler auf Gerätefunktionen zu begrenzen oder legen Entwicklung zu halten, während zusätzliche Mittel angehoben. Dies trägt zu einer drastischen Verlangsamung des Entwicklungsprozesses, da ein großer Teil der medizinischen Vorrichtungen wieder<html> erfordern Umsetzung von komplexen Funktionen. Es ist auch schwierig, die kostspielige Entwicklung solcher Vorrichtungen seit Proof-of-Concept-Daten oft noch nicht etabliert finanzieren. Wir stießen auf dieses Straßensperre in einem aktuellen Projekt in diesem Labor, das die Entwicklung eines Silikon intravaginale Sonde mit umspritzten elektrischen und optischen Sensoren, die eine becherartige Spitze erforderlich, um zu bestimmten Geometrien entsprechen Gebärmutterhalskrebs beteiligt. Die in diesem Artikel beschriebenen Verfahren dokumentiert unser Versuch, diesen Teufelskreis zu umgehen und schnell zu erreichen Proof-of-Concept für LIM medizinische Geräte. Die in Abbildung 1 gezeigten Technik dekonstruiert das LIM-Prozess in fünf Hauptaktivitäten: (1) Formenbau und Produktion, (2) Formanordnung (3) Elastomermischung, (4) Elastomer-Injektion, und (5) Elastomer Aushärtung und Entformung. pg &quot;width =&quot; 600 &quot;/&gt; .. Abbildung 1 Protokoll Übersicht des Protokolls, das beinhaltet: (1a) die Schaffung einer Form mit Computer-Aided-Design-Tools, (1b), 3D-Druck der Formteile, (2) Zusammensetzen der Formstücke mit Gewindestangen und Schrauben ( 3) Mischen von flüssigen Elastomeren und Einlegen in eine Spritze, (4) Einspritzen des flüssigen Elastomers in die Form unter Verwendung einer modifizierten Exsikkator (5a) Härten des Elastomers in einem temperaturgeregelten Ofen, und (5b) Entformen des gehärteten Elastomers Gerät die Formstücke. Mold-Design beinhaltet die Entwicklung einer Form Master in Computer-Aided Design (CAD) Software, Subtraktion der Form-Master aus einem massiven Block und Definition von Formtrennlinien. Formteile erstellt werden und unter Verwendung von Schrauben, Stangen und Muttern mit umspritzten Komponenten in den Formhohlraum positioniert ist dann zusammengebaut. Elastomer mixing beinhaltet die Kombination von Teilen A und B des Rohstoff-und Entgasung, um mögliche Hohlräume in dem Material zu entfernen. Als nächstes Elastomer Injektion beinhaltet druckbetriebenen Füllung des Formhohlraumes, gefolgt von Härten Elastomer in einem temperaturgesteuerten Ofen einer chemischen Vernetzung der Polymerketten zu gewährleisten. Das Aufbrechen der Spritzgussverfahren in dieser Schritte ermöglicht es uns, traditionelle LIM Geräte für kostengünstige Alternativen zu verzichten. Zum Beispiel, statt der Bearbeitung eines Metallform oder Gießen eine Silikon-Gummi-Form aus einer Form-Master, die Formen von der in dieser Handschrift beschriebenen Protokoll erstellt wurden aus Acrylnitril-Butadien-Styrol (ABS)-Kunststoff unter Verwendung einer geschmolzenen-Deposition Modeling (FDM) 3D erstellt Drucker 8,9. Im Vergleich zu den Bau-oder Metallformen SLA Formen, ist FDM in der Regel ein kostengünstiger und schneller Prozess. Ziemlich komplexe Formen können schnell auf einer Inhouse-3D-Drucker gedruckt werden, oder billig von einem der vielen Vertrags printin 3D produziertg-Dienste zur Verfügung. So wurde beispielsweise eine komplexe acht-teilige 3D-gedruckten Form verwendet und in den 14 und 15 gezeigt, die demonstriert intravaginale Sonde in der repräsentative Ergebnisse Schnitt vergossen. Alle Teile für diese Form kann in etwa 1,5 Tage auf einer Inhouse-3D-Drucker ausgedruckt werden. Durchlaufzeiten für einfachere Formen können ein paar Stunden sein. Die Gesamtlänge der Zeit notwendig, um ein Gerät mit FDM 3D-Drucker um Formen zu erstellen Prototypen ist vergleichbar mit der Zeit, um eine Form aus Silikonkautschuk gegossen und eine Polyurethan-Prototyp erforderlich. Allerdings mit FDM 3D-Drucker um Formen erstellen können mehrere Dinge, die nicht einfach mit einem Silikonform erreicht werden kann: (1) viele duroplastischen Elastomeren verwendet werden, sofern der 3D-gedruckte Form kann die erforderlichen Härtetemperaturen vertragen, (2) komplexe Geometrien kann unter Verwendung vieler verschiedener Formteile und Trennlinien erzeugt werden, und (3) die Verwendung von starren Formstücke erlaubt eine genaue und reproduzierbareBLE Ausrichtung umspritzten Bauteilen innerhalb des Formhohlraums. Anstelle der Verwendung eines herkömmlichen LIM Maschine, welches das Mischen kombiniert, Injektion, und Härten ist es möglich, einen Labormischer zu verwenden, um ein homogenes Mischen, ein modifiziertes Exsikkator zur Injektion, und eine Standard-Temperatur-gesteuerten Ofen zum Aushärten zu gewährleisten. Das Einspritzsystem wurde mit off-the-shelf-Komponenten erstellt und beinhaltet die Zugabe eines positiven Druckversorgungsleitung in den Exsikkator, der mit einer Spritze mit Misch Elastomer gefüllt verbindet. Unterdruckkammer in Tisch Exsikkatoren wird typischerweise durch eine Dreiwegeventil zwischen den Kammern, eine Vakuumleitung und der Atmosphäre gesteuert. Das modifizierte Exsikkator fügt eine positive Druckversorgungsleitung zur Zuführung der Rückseite eines Spritzenkolbens. Dies ermöglicht die Schaffung eines 40-50 psi Druckdifferenz, die ausreichend für flüssige Material Injektion in den Formhohlraum ist. Diese Technik erlaubt es uns, produce Silikon intravaginale Sonden mit umspritzten elektrischen und optischen Sensoren, die Proof-of-Concept-Daten für eine klinische Phase-I-Studie zu sammeln. Silikon wurde aufgrund der Notwendigkeit für die biologische Inertheit als auch die Fähigkeit, mit einer Vielzahl von Verfahren ausgewählt 10,11 sterilisieren. Darüber hinaus benötigt das Gerät eine komplexe und unkonventionelle becherartige Geometrie an der Spitze der Sonde, wo Sensoren sind so angeordnet, mit dem Gebärmutterhals-Schnittstelle. Ohne die Verwendung der beschriebenen Technik wäre es ein sehr teurer und langwieriger Prozess, um diese Geräte zu produzieren. Diese Anpassung der LIM-Verfahren reduziert die Kosten und Anforderungen an die Ausrüstung, wenn zum traditionellen LIM Verfahren verglichen, so dass es praktisch, eine schnelle und iterativen Ansatz zur Gestaltung von Elastomer-Geräte erlassen.

<table border="0" cellpadding="0" cellspacing="0" width="1434">
	<tbody>
		<tr>
			<td>ABS Model Material</td>
			<td>Stratasys</td>
			<td>P430</td>
			<td>Model Material for uPrint Plus SE (Step: Mold Design &#38; Production)</td>
		</tr>
		<tr>
			<td>Soluble Support Material</td>
			<td>Stratasys</td>
			<td>SR-30</td>
			<td>Support Material for uPrint Plus SE (Step: Mold Design &#38; Production)</td>
		</tr>
		<tr>
			<td>Underwater Silicone Sealant, 2.8 Oz Tube, Clear</td>
			<td>McMaster-Carr Supply Company</td>
			<td>7327A21</td>
			<td>Silicone RTV for sealing gaps at mold parting lines (Step: Mold Assembly)</td>
		</tr>
		<tr>
			<td>Tubing, 1/8&#34; ID, 1/4&#34; OD, 1/16&#34; Wall Thickness, Ultra-chemical-resistant Tygon PVC, Clear</td>
			<td>McMaster-Carr Supply Company</td>
			<td>5046K11</td>
			<td>Forms runner/sprue adapter between mold and syringe with elastomer (Step: Elastomer Mixing)</td>
		</tr>
		<tr>
			<td>Coupling, Adapter, Straight, Male Quick-turn (Luer lock) X 1/8&#34; Tube Barb, Nylon</td>
			<td>McMaster-Carr Supply Company</td>
			<td>51525K123</td>
			<td>Connect runner/sprue between mold and syringe with elastomer (Step: Elastomer Mixing)</td>
		</tr>
		<tr>
			<td>Coupling, Adapter, Staight, Female Quick-turn (Luer lock) X 1/8&#34; Tube Barb, Nylon</td>
			<td>McMaster-Carr Supply Company</td>
			<td>51525K213</td>
			<td>Connect runner/sprue between mold and syringe with elastomer (Step: Elastomer Mixing)</td>
		</tr>
		<tr>
			<td>Cap, Female Quick-turn (Luer lock), Nylon</td>
			<td>McMaster-Carr Supply Company</td>
			<td>51525K315</td>
			<td>Cap to prevent silicone from leaking out of mold after injection (Step: Elastomer Mixing)</td>
		</tr>
		<tr>
			<td>Liquid Silicone Rubber (LSR) 30 - 10:1, Implant Grade</td>
			<td>Applied Silicone Corporation</td>
			<td>PN40029</td>
			<td>Substitute with the elastomer of your choice.&#160; This is the one used for the intravaginal probe (Step: Elastomer Mixing)</td>
		</tr>
		<tr>
			<td>Syringes (BD), 1mL Slip-Tip, non-sterile clean, bulk</td>
			<td>Cole-Parmer</td>
			<td>WU-07945-00</td>
			<td>Syringes for transfering elastomer material (Step: Elastomer Mixing)</td>
		</tr>
		<tr>
			<td>Syringes (BD), 1mL Slip-Tip, non-sterile clean, bulk</td>
			<td>Cole-Parmer</td>
			<td>WU-07945-04</td>
			<td>Syringes for transfering elastomer material (Step: Elastomer Mixing)</td>
		</tr>
		<tr>
			<td>Syringe, 20mL, Open Bore, Solid Ring Plunger and Grip</td>
			<td>Qosina Corporation</td>
			<td>C1200</td>
			<td>Syringes for transfering elastomer material.&#160; Open bore is used for very viscous elastomers. (Step: Elastomer Mixing)</td>
		</tr>
		<tr>
			<td>Needle (BD), Non-sterile Clean with Shields, 18 gauge X 1.5&#34; Lg., Stainless Steel, BD Bulk&#160;</td>
			<td>Cole-Parmer</td>
			<td>WU-07945-76</td>
			<td>Used for removing air column between syringe plunger and elastomer (Step: Elastomer Mixing)</td>
		</tr>
		<tr>
			<td>Plastic Cups, 12 Oz., Clear</td>
			<td>Safeway</td>
			<td>N/A</td>
			<td>Used for mixing silicone in THINKY Mixer (Step: Elastomer Mixing)</td>
		</tr>
		<tr>
			<td>Polyethylene Bag, Open-Top, Flat, 5&#34; Width X 6&#34; Height, 2-MIL Thk.</td>
			<td>McMaster-Carr Supply Company</td>
			<td>1928T68</td>
			<td>Used for mixing silicone in THINKY Mixer (Step: Elastomer Mixing)</td>
		</tr>
		<tr>
			<td>Rubber Band, Latex Free, Orange, Size 64, 3-1/2&#34; L X 1/4&#34; W</td>
			<td>McMaster-Carr Supply Company</td>
			<td>12205T96</td>
			<td>Used for mixing silicone in THINKY Mixer (Step: Elastomer Mixing)</td>
		</tr>
		<tr>
			<td>Parafilm Wrap, 4&#34;W</td>
			<td>Cole-Parmer</td>
			<td>EW-06720-40</td>
			<td>Used for mixing silicone in THINKY Mixer (Step: Elastomer Mixing)</td>
		</tr>
		<tr>
			<td>Syringe Barrels with Stoppers, Luer Lock, Air Operated,&#160; 50mL</td>
			<td>EWD Solutions</td>
			<td>JEN-JG50A-15</td>
			<td>Smaller syringes can be used if less elastomer is required, but make sure it is compatible with Air Operated Syringe Adapter in injection chamber (Step: Elastomer Mixing)</td>
		</tr>
		<tr>
			<td>Sealant Tape, Pipe Thread, 50&#39;Lg X 1/4&#34; W, .0028&#34; Thk, 0.5 G/CC Specific Gravity&#160;</td>
			<td>McMaster-Carr Supply Company</td>
			<td>4591K11</td>
			<td>Teflon Tape for air-tight seals around at threads (Step: Elastomer Injection)</td>
		</tr>
		<tr>
			<td>Scalpel Blades, Disposable, No. 22</td>
			<td>VWR</td>
			<td>21909-646</td>
			<td>Used for cutting tubing and demolding (Step: Curing &#38; Demolding)</td>
		</tr>
		<tr>
			<td>Kimwipes</td>
			<td>VWR</td>
			<td>21903-005</td>
			<td>&#160;(Step: Curing &#38; Demolding)</td>
		</tr>
		<tr>
			<td>2-Propanol, J. T. Baker</td>
			<td>VWR</td>
			<td>JT9334-3</td>
			<td>&#160;(Step: Curing &#38; Demolding)</td>
		</tr>
		<tr>
			<td>uPrint Plus SE 3D Printer</td>
			<td>Stratasys</td>
			<td>uPrint Plus SE</td>
			<td>Other 3D printers can be used (Step: Mold Design &#38; Production)</td>
		</tr>
		<tr>
			<td>Screw, Cap, Hex Head,&#160; 1/4&#34;-28 , 2-1/2&#34; Lg, 18-8 Stainless Steel</td>
			<td>McMaster-Carr Supply Company</td>
			<td>92198A115</td>
			<td>Screws used with nuts to compress mold (Step: Mold Assembly)</td>
		</tr>
		<tr>
			<td>Nut, Hex, 1/4&#34;-28, 7/16&#34; Wd, 7/32&#34; Height, 18-8 Stainless Steel&#160;</td>
			<td>McMaster-Carr Supply Company</td>
			<td>91845A105</td>
			<td>Screws used with nuts to compress mold (Step: Mold Assembly)</td>
		</tr>
		<tr>
			<td>Stud, Fully Threaded, 1/4&#34;-28, 1&#34; Lg, 18-8 Stainless Steel&#160;</td>
			<td>McMaster-Carr Supply Company</td>
			<td>95412A567</td>
			<td>Threaded-rods can be cut to desired length and are used with nutes to compress mold (Step: Mold Assembly)</td>
		</tr>
		<tr>
			<td>Planetary Centrifugal Mixer</td>
			<td>THINKY USA Inc.</td>
			<td>ARE-310</td>
			<td>Mixers are strongly recommended for fine mixing and to reduce degassing time, but hand mixing is fine (Step: Elastomer Mixing)</td>
		</tr>
		<tr>
			<td>Laboratory Weigh Scale</td>
			<td>Mettler-Toledo International Inc.</td>
			<td>EL602</td>
			<td>&#160;(Step: Elastomer Mixing)</td>
		</tr>
		<tr>
			<td>Desiccant Vacuum Canister, Reusable,&#160; 10-3/4&#34; OD</td>
			<td>McMaster-Carr Supply Company</td>
			<td>2204K7</td>
			<td>This desiccator is used for degassing the elastomer (Step: Elastomer Mixing)</td>
		</tr>
		<tr>
			<td>Custom 3D-Printed Mixer-to-Cup Adapter</td>
			<td>N/A</td>
			<td>N/A</td>
			<td>Modeled in Solidworks CAD and 3D printed (Step: Elastomer Mixing)</td>
		</tr>
		<tr>
			<td>Tubing, Smooth Bore, 1/4&#34; ID, 1/2&#34; OD, 1/8&#34; Wall Thickness, High Purity Tygon PVC, Clear</td>
			<td>McMaster-Carr Supply Company</td>
			<td>5624K51</td>
			<td>Tubing outside of Desiccator (Step: Elastomer Injection)</td>
		</tr>
		<tr>
			<td>Tubing, Smooth Bore, 3/8&#34; ID, 5/8&#34; OD, 1/8&#34; Wall Thickness, High Purity Tygon PVC, Clear</td>
			<td>McMaster-Carr Supply Company</td>
			<td>5624K52</td>
			<td>Tubing to adapt to Air/Vacuum Supply (Step: Elastomer Injection)</td>
		</tr>
		<tr>
			<td>Coupling, Reducer, Straight, Vacuum Barb 3/8&#34; Tube ID X Vacuum Barb 1/4&#34; Tube ID, Brass</td>
			<td>McMaster-Carr Supply Company</td>
			<td>44555K188</td>
			<td>Adapt Tubing outside Desiccator to Tubing leading to Air/Vacuum Supply (Step: Elastomer Injection)</td>
		</tr>
		<tr>
			<td>Clamp, Hose &#38; Tube, Worm-Drive, for 7/32&#34; to 5/8&#34; OD tube, 5/16&#34; Wd., 316 SS</td>
			<td>McMaster-Carr Supply Company</td>
			<td>5011T141</td>
			<td>Used on tubing to create Air/Vacuum-tight seal at junctions (Step: Elastomer Injection)</td>
		</tr>
		<tr>
			<td>Clamp, Hose, Smooth-Band Worm-Drive, for 1/2&#34; to 3/4&#34; OD tube, 3/8&#34; Wd., 304 SS</td>
			<td>McMaster-Carr Supply Company</td>
			<td>5574K13</td>
			<td>Used on tubing to create Air/Vacuum-tight seal at junctions (Step: Elastomer Injection)</td>
		</tr>
		<tr>
			<td>Coupling, Tee, Vacuum Barb 1/4&#34; Tube ID, Brass</td>
			<td>McMaster-Carr Supply Company</td>
			<td>44555K138</td>
			<td>Tee Junction between Vacuum, Three-way T-valve on Desiccator, and Three-way L-valve (Step: Elastomer Injection)</td>
		</tr>
		<tr>
			<td>Coupling, Tee, 1/4 NPT Female X Female X Male, Brass</td>
			<td>McMaster-Carr Supply Company</td>
			<td>50785K222</td>
			<td>Tee Junction between Pressure Gauge, Chamber, and Three-way L-valve (Step: Elastomer Injection)</td>
		</tr>
		<tr>
			<td>Valve, Ball, Straight, T-Handle, 1/4 NPT Female X Male, Brass</td>
			<td>McMaster-Carr Supply Company</td>
			<td>4082T42</td>
			<td>Three-way L-valve (Step: Elastomer Injection)</td>
		</tr>
		<tr>
			<td>Coupling, Adapter, Straight, Vacuum Barb 1/4&#34; ID Tube X 1/4 NPT Male, Brass</td>
			<td>McMaster-Carr Supply Company</td>
			<td>44555K132</td>
			<td>Adapter for Three-way L-valve-to-Tubing (Step: Elastomer Injection)</td>
		</tr>
		<tr>
			<td>Saw, Hole, Bimetal. 1-3/8&#34; OD, 1-1/2&#34; Cutting Depth</td>
			<td>McMaster-Carr Supply Company</td>
			<td>4066A25</td>
			<td>Used to cut holes in Desiccator for throughwall fittings (Step: Elastomer Injection)</td>
		</tr>
		<tr>
			<td>Arbor, 9/16&#34; to 1-3/16&#34; Saw, 1/4&#34; Hex</td>
			<td>McMaster-Carr Supply Company</td>
			<td>4066A76</td>
			<td>Used to cut holes in Desiccator for throughwall fittings (Step: Elastomer Injection)</td>
		</tr>
		<tr>
			<td>Arbor Adapter for 1-1/4&#34; Thru 6&#34; Dia Hole Saws</td>
			<td>McMaster-Carr Supply Company</td>
			<td>4066A77</td>
			<td>Used to cut holes in Desiccator for throughwall fittings (Step: Elastomer Injection)</td>
		</tr>
		<tr>
			<td>Coupling, Straight, Through-Wall, 1/2 NPT Female, Polypropylene</td>
			<td>McMaster-Carr Supply Company</td>
			<td>36895K141</td>
			<td>Throughwall fittings leading to Pressure/Vacuum Gauges (Step: Elastomer Injection)</td>
		</tr>
		<tr>
			<td>Coupling, Adapter, Straight, Reducing,&#160; Bushing, Hex, 1/2 NPT Male X 1/4 NPT Female, Brass</td>
			<td>McMaster-Carr Supply Company</td>
			<td>4429K422</td>
			<td>Reducing tube diameter inside the Desiccator to adapt to Air-operated Syringe System (Step: Elastomer Injection)</td>
		</tr>
		<tr>
			<td>Coupling, Adapter, Straight, Reducing, Bushing, Hex, 1/4 NPT Male X 1/8 NPT Female, Brass</td>
			<td>McMaster-Carr Supply Company</td>
			<td>4757T91</td>
			<td>Reducing tube diameter inside the Desiccator to adapt to Air-operated Syringe System (Step: Elastomer Injection)</td>
		</tr>
		<tr>
			<td>Coupling, Adapter, Straight, Vacuum Barb 1/4&#34; ID Tube X 1/8 NPT Female, Brass</td>
			<td>McMaster-Carr Supply Company</td>
			<td>44555K124</td>
			<td>Reducing tube diameter inside the Desiccator to adapt to Air-operated Syringe System (Step: Elastomer Injection)</td>
		</tr>
		<tr>
			<td>Syringe Adapters, Air Operated, 30/50mL</td>
			<td>EWD Solutions</td>
			<td>JEN-JG30A-X6</td>
			<td>Air operated syringe adapter on the inside of the Desiccator; must be compatible with syringes used to hold elastomer (Step: Elastomer Injection)</td>
		</tr>
		<tr>
			<td>Gauge, Dual-Scale Vacuum, 2-1/2&#34; Dial, 1/4 NPT Male, Bottom Connector, 30&#34; Hg-0, Steel Case</td>
			<td>McMaster-Carr Supply Company</td>
			<td>4002K11</td>
			<td>Vacuum Gauge (Step: Elastomer Injection)</td>
		</tr>
		<tr>
			<td>Gauge, Dual-Scale Vacuum and Compound, 3-1/2&#34; Dial, 1/4 NPT Male, Center Back, 30&#34; Hg-0, 100 PSI, Steel Case</td>
			<td>McMaster-Carr Supply Company</td>
			<td>4004K616</td>
			<td>Pressure Gauge leading to Air-operated Syringe System (Step: Elastomer Injection)</td>
		</tr>
		<tr>
			<td>Oven, Vacuum, Isotemp, Economy&#160;</td>
			<td>Fisher Scientific</td>
			<td>280A</td>
			<td>Standard non-vacuum oven can be used (Step: Curing &#38; Demolding)</td>
		</tr>
		<tr>
			<td>Solidworks CAD</td>
			<td>Dassault Syst&#232;mes</td>
			<td>Solidworks Research Subscription</td>
			<td>Other CAD Software can be used for mold master and mold design (Step: Mold Design &#38; Production)</td>
		</tr>
	</tbody>
</table>

rapid and low-cost prototyping of medical devices using 3d printed molds for liquid injection molding

Biologisch inert Elastomeren wie Silikon sind günstig Materialien für medizinische Gerätefertigung, sondern Formen und Härten dieser Elastomeren mit herkömmlichen Flüssigspritzgussverfahren kann ein teurer Prozess durch Werkzeug-und Gerätekosten sein. Als ein Ergebnis wurde es traditionell unpraktisch, Flüssigspritzgießen für kostengünstige, Rapid Prototyping Anwendungen. Wir haben eine Methode für die schnelle und kostengünstige Herstellung von flüssigen Elastomerspritzguss Geräte, Fused Deposition Modeling 3D-Drucker für den Formenbau und einem modifizierten Exsikkator als Injektion System nutzt entwickelt. Geringe Kosten und eine schnelle Bearbeitungszeit bei dieser Technik senken die Barriere iterativ Gestaltung und Prototyping komplexer Elastomer-Geräte. Darüber hinaus können CAD-Modelle in diesem Prozess entwickelt, später für die Metall-Formwerkzeugentwicklung angepasst werden, was einen einfachen Übergang zu einer herkömmlichen Spritzgussverfahren. Wir haben diese Technik verwendet, um die Herstellung intravaginal Sonden mit komplexen Geometrien sowie über Umspritzen von Metallteilen, die die Tools häufig innerhalb einer akademischen Forschungslabor. Jedoch kann diese Technik leicht an spritzgegossenen Vorrichtungen für viele andere Anwendungen zu schaffen.

Die Form und die intravaginale Sonde in den 14 und 15 zeigt repräsentative Ergebnisse der in diesem Artikel vorgestellten Verfahren. <img alt="14" fo:content-width="5in" src="/files/ftp_upload/51745/51745fig14highres.jpg" width="500" /> Abbildung 14. Vollständig montierte Mold. Komplett montiert Form für intravaginale Sonde Gerät. <p class="jove_content" fo:keep-together.within-page="always"...

Watch this Scientific Journal Video about Rapid and Low-cost Prototyping of Medical Devices Using 3D Printed Molds for Liquid Injection Molding at JoVE.com

Rapid and Low-cost Prototyping of Medical Devices Using 3D Printed Molds for Liquid Injection Molding

Wir haben ein Verfahren zur kostengünstigen und Rapid Prototyping von flüssigen Elastomergummispritzguss Geräte mithilfe Fused Deposition Modeling 3D-Drucker für den Formenbau und einem modifizierten Exsikkator als Flüssigkeitsinjektionssystem entwickelt.

Schnelle und Low-Cost-Prototyping für Medizinische Geräte mit 3D Printed Formen für Liquid Injection Molding

Biologically inert elastomers such as silicone are favorable materials for medical device fabrication, but forming and curing these elastomers using ...

rapid-low-cost-prototyping-medical-devices-using-3d-printed-molds-for

Research

JoVE Journal

Bioengineering

19.7K Aufrufe.  University of California, San Francisco.  Wir haben ein Verfahren zur kostengünstigen und Rapid Prototyping von flüssigen Elastomergummispritzguss Geräte mithilfe Fused Deposition Modeling 3D-Drucker für den Formenbau und einem modifizierten Exsikkator als Flüssigkeitsinjektionssystem entwickelt. 

Serie: Rapid and Low-cost Prototyping of Medical Devices Using 3D Printed Molds for Liquid Injection Molding

High Throughput Microfluidic Rapid and Low Cost Prototyping Packaging Methods

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

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

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

Forschung

Biotechnik

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.

We demonstrate the use of patterned aerosol adhesives to construct 3D paper microfluidic devices. This method of adhesive application forms semi-permanent bonds between layers, enabling single-use devices to be non-destructively disassembled after use and to ease folding complex nonplanar structures.

Mit Adhesive Patterning 3D Paper Mikrofluidik-Vorrichtungen bauen

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

High-throughput Identification of Bacteria Repellent Polymers for Medical Devices

Medical devices are often associated with hospital-acquired infections, which place enormous strain on patients and the healthcare system as well as contributing to antimicrobial resistance. One possible avenue for the reduction of device-associated infections is the identification of bacteria-repellent polymer coatings for these devices, which would prevent bacterial binding at the initial attachment step. A method for the identification of such repellent polymers, based on the parallel screening of hundreds of polymers using a microarray, is described here. This high-throughput method resulted in the identification of a range of promising polymers that resisted binding of various clinically relevant bacterial species individually and also as multi-species communities. One polymer, PA13 (poly(methylmethacrylate-co-dimethylacrylamide)), demonstrated significant reduction in attachment of a number of hospital isolates when coated onto two commercially available central venous catheters. The method described could be applied to identify polymers for a wide range of applications in which modification of bacterial attachment is important.

A high-throughput microarray method for the identification of polymers which reduce bacterial surface binding on medical devices is described.

Hochdurchsatz-Identifizierung von Bakterien abstoßenden Polymere für medizinische Geräte

Medical devices are often associated with hospital-acquired infections, which place enormous strain on patients and the healthcare system as well as ...

Scaling of Engineered Vascular Grafts Using 3D Printed Guides and the Ring Stacking Method

Coronary artery disease remains a leading cause of death, affecting millions of Americans. With the lack of autologous vascular grafts available, engineered grafts offer great potential for patient treatment. However, engineered vascular grafts are generally not easily scalable, requiring manufacture of custom molds or polymer tubes in order to customize to different sizes, constituting a time-consuming and costly practice. Human arteries range in lumen diameter from about 2.0-38 mm and in wall thickness from about 0.5-2.5 mm. We have created a method, termed the "Ring Stacking Method," in which variable size rings of tissue of the desired cell type, demonstrated here with vascular smooth muscle cells (SMCs), can be created using guides of center posts to control lumen diameter and outer shells to dictate vessel wall thickness. These tissue rings are then stacked to create a tubular construct, mimicking the natural form of a blood vessel. The vessel length can be tailored by simply stacking the number of rings required to constitute the length needed. With our technique, tissues of tubular forms, similar to a blood vessel, can be readily manufactured in a variety of dimensions and lengths to meet the needs of the clinic and patient.

Scalable engineered blood vessels would improve clinical applicability. Using easily sizable 3D-printed guides, rings of vascular smooth muscle were created and stacked into a tubular form, forming a vascular graft. Grafts can be sized to meet the range of human coronary artery dimensions by simply changing the 3D-printed guide size.

Die Skalierung von Engineered Gefäßprothesen Mit 3D-gedruckte Führer und den Ring Stapelverfahren

Coronary artery disease remains a leading cause of death, affecting millions of Americans. With the lack of autologous vascular grafts available, ...

Synthesis of Biocompatible Liquid Crystal Elastomer Foams as Cell Scaffolds for 3D Spatial Cell Cultures

Here, we present a step-by-step preparation of a 3D, biodegradable, foam-like cell scaffold. These scaffolds were prepared by cross-linking star block co-polymers featuring cholesterol units as side-chain pendant groups, resulting in smectic-A (SmA) liquid crystal elastomers (LCEs). Foam-like scaffolds, prepared using metal templates, feature interconnected microchannels, making them suitable as 3D cell culture scaffolds. The combined properties of the regular structure of the metal foam and of the elastomer result in a 3D cell scaffold that promotes not only higher cell proliferation compared to conventional porous templated films, but also better management of mass transport (i.e., nutrients, gases, waste, etc.). The nature of the metal template allows for the easy manipulation of foam shapes (i.e., rolls or films) and for the preparation of scaffolds of different pore sizes for different cell studies while preserving the interconnected porous nature of the template. The etching process does not affect the chemistry of the elastomers, preserving their biocompatible and biodegradable nature. We show that these smectic LCEs, when grown for extensive time periods, enable the study of clinically relevant and complex tissue constructs while promoting the growth and proliferation of cells.

This study presents a methodology to prepare 3D, biodegradable, foam-like cell scaffolds based on biocompatible side-chain liquid crystal elastomers (LCEs). Confocal microscopy experiments show that foam-like LCEs allow for cell attachment, proliferation, and the spontaneous alignment of C2C12s myoblasts.

Synthese von biokompatiblen Liquid Crystal Elastomerschäume als Zellgerüste für 3D Spatial Zellkulturen

Here, we present a step-by-step preparation of a 3D, biodegradable, foam-like cell scaffold. These scaffolds were prepared by cross-linking star block ...

Fabrication of Custom Agarose Wells for Cell Seeding and Tissue Ring Self-assembly Using 3D-Printed Molds

Engineered tissues are being used clinically for tissue repair and replacement, and are being developed as tools for drug screening and human disease modeling. Self-assembled tissues offer advantages over scaffold-based tissue engineering, such as enhanced matrix deposition, strength, and function. However, there are few available methods for fabricating 3D tissues without seeding cells on or within a supporting scaffold. Previously, we developed a system for fabricating self-assembled tissue rings by seeding cells into non-adhesive agarose wells. A polydimethylsiloxane (PDMS) negative was first cast in a machined polycarbonate mold, and then agarose was gelled in the PDMS negative to create ring-shaped cell seeding wells. However, the versatility of this approach was limited by the resolution of the tools available for machining the polycarbonate mold. Here, we demonstrate that 3D-printed plastic can be used as an alternative to machined polycarbonate for fabricating PDMS negatives. The 3D-printed mold and revised mold design is simpler to use, inexpensive to produce, and requires significantly less agarose and PDMS per cell seeding well. We have demonstrated that the resulting agarose wells can be used to create self-assembled tissue rings with customized diameters from a variety of different cell types. Rings can then be used for mechanical, functional, and histological analysis, or for fabricating larger and more complex tubular tissues.

This protocol describes a platform for fabricating self-assembled tissue rings in variable sizes using a customized 3D-printed plastic mold. PDMS negatives are cured in the 3D-printed mold; then agarose is cast in the cured PDMS negatives. Cells are seeded into the resulting agarose wells where they aggregate into tissue rings.

Herstellung von benutzerdefinierten Agarose Brunnen für die Aussaat von Zelle und Gewebe Ring Selbstmontage mit 3D-Druck Formen

Engineered tissues are being used clinically for tissue repair and replacement, and are being developed as tools for drug screening and human disease ...

3D Printed Porous Cellulose Nanocomposite Hydrogel Scaffolds

This work demonstrates the use of three-dimensional (3D) printing to produce porous cubic scaffolds using cellulose nanocomposite hydrogel ink, with controlled pore structure and mechanical properties. Cellulose nanocrystals (CNCs, 69.62 wt%) based hydrogel ink with matrix (sodium alginate and gelatin) was developed and 3D printed into scaffolds with uniform and gradient pore structure (110-1,100 &#181;m). The scaffolds showed compression modulus in the range of 0.20-0.45 MPa when tested in simulated in vivo conditions (in distilled water at 37 &#176;C). The pore sizes and the compression modulus of the 3D scaffolds matched with the requirements needed for cartilage regeneration applications. This work demonstrates that the consistency of the ink can be controlled by the concentration of the precursors and porosity can be controlled by the 3D printing process and both of these factors in return defines the mechanical properties of the 3D printed porous hydrogel scaffold. This process method can therefore be used to fabricate structurally and compositionally customized scaffolds according to the specific needs of patients.&#160;

The three critical steps of this protocol are i) developing the right composition and consistency of the cellulose hydrogel ink, ii) 3D printing of scaffolds into various pore structures with good shape fidelity and dimensions and iii) demonstration of the mechanical properties in simulated body conditions for cartilage regeneration.

3D-Druck poröse Zellulose Nanocomposites Hydrogel Gerüste

This work demonstrates the use of three-dimensional (3D) printing to produce porous cubic scaffolds using cellulose nanocomposite hydrogel ink, with ...

Design of an Open-Source, Low-Cost Bioink and Food Melt Extrusion 3D Printer

Three-dimensional (3D) printing is an increasingly popular manufacturing technique that allows highly complex objects to be fabricated with no retooling costs. This increasing popularity is partly driven by falling barriers to entry such as system set-up costs and ease of operation. The following protocol presents the design and construction of an Additive Manufacturing Melt Extrusion (ADDME) 3D printer for the fabrication of custom parts and components. ADDME has been designed with a combination of 3D-printed, laser-cut, and online-sourced components. The protocol is arranged into easy-to-follow sections, with detailed diagrams and parts lists under the headings of framing, y-axis and bed, x-axis, extrusion, electronics, and software. The performance of ADDME is evaluated through extrusion testing and 3D printing of complex objects using viscous cream, chocolate, and Pluronic F-127 (a model for bioinks). The results indicate that ADDME is a capable platform for the fabrication of materials and constructs for use in a wide range of industries. The combination of detailed diagrams and video content facilitates access to low-cost, easy-to-operate equipment for individuals interested in 3D printing of complex objects from a wide range of materials.

The aim of this work is to design and construct a reservoir-based melt extrusion three-dimensional printer made from open-source and low-cost components for applications in the biomedical and food printing industries.

Design eines 3D-Druckers für Open-Source- und Low-Cost-Bioink und Lebensmittelschmelzextrusion

Three-dimensional (3D) printing is an increasingly popular manufacturing technique that allows highly complex objects to be fabricated with no retooling ...

Rapid Fabrication of Custom Microfluidic Devices for Research and Educational Applications

Microfluidic devices allow for the manipulation of fluids, particles, cells, micro-sized organs or organisms in channels ranging from the nano to submillimeter scales. A rapid increase in the use of this technology in the biological sciences has prompted a need for methods that are accessible to a wide range of research groups. Current fabrication standards, such as PDMS bonding, require expensive and time consuming lithographic and bonding techniques. A viable alternative is the use of equipment and materials that are easily affordable, require minimal expertise and allow for the rapid iteration of designs. In this work we describe a protocol for designing and producing PET-laminates (PETLs), microfluidic devices that are inexpensive, easy to fabricate, and consume significantly less time to generate than other approaches to microfluidics technology. They consist of thermally bonded film sheets, in which channels and other features are defined using a craft cutter. PETLs solve field-specific technical challenges while dramatically reducing obstacles to adoption. This approach facilitates the accessibility of microfluidics devices in both research and educational settings, providing a reliable platform for new methods of inquiry.

Here we present a protocol to design and fabricate custom microfluidic devices with minimal financial and time investment. The aim is to facilitate the adoption of microfluidic technologies in biomedical research laboratories and educational settings.

Schnelle Herstellung von kundenspezifischen mikrofluidischen Geräten für Forschungs- und Bildungsanwendungen

Microfluidic devices allow for the manipulation of fluids, particles, cells, micro-sized organs or organisms in channels ranging from the nano to ...

Low-Cost, Volume-Controlled Dipstick Urinalysis for Home-Testing

Dipstick urinalysis provides quick and affordable estimations of multiple physiological conditions but requires good technique and training to use accurately. Manual performance of dipstick urinalysis relies on good human color vision, proper lighting control, and error-prone, time-sensitive comparisons to chart colors. By automating the key steps in the dipstick urinalysis test, potential sources of error can be eliminated, allowing self-testing at home. We describe the steps necessary to create a customizable device to perform automated urinalysis testing in any environment. The device is cheap to manufacture and simple to assemble. We describe the key steps involved in customizing it for the dipstick of choice and for customizing a mobile phone app to analyze the results. We demonstrate its use to perform urinalysis and discuss the critical measurements and fabrication steps necessary to ensure robust operation. We then compare the proposed method to the dip-and-wipe method, the gold standard technique for dipstick urinalysis.

Dipstick urinalysis is a quick and affordable method of assessing one&#8217;s personal state of health. We present a method to perform accurate, low-cost dipstick urinalysis that removes the primary sources of error associated with traditional dip-and-wipe protocols and is simple enough to be performed by lay users at home.