Este trabajo fue apoyado en parte a través NSFDMI-0508454, NSF / LEQSF (2006)-Pfund-53, la NSF-CMMI-0.811.888, y subvenciones de la NSF-CMMI-0900595.

<ol>
	<li>Menon, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conducting+polymers:+Nobel+Prize+in+Chemistry,+2000.">Conducting polymers: Nobel Prize in Chemistry, 2000.</a> Current Science. 79, 1632 (2000).</li><li>Inzelt, G., Pineri, M., Schultze, J. W., Vorotyntsev, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electron+and+proton+conducting+polymers:+recent+developments+and+prospects.">Electron and proton conducting polymers: recent developments and prospects.</a> Electrochimica Acta. 45, 2403 (2000).</li><li>Adhikari, B., Majumdar, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polymers+in+sensor+applications.">Polymers in sensor applications.</a> Progress in Polymer Science. 29, 699 (2004).</li><li>Chakraborty, A., Liu, X., Parthasarathi, G., Luo, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+intermediate-layer+lithography+method+for+generating+multiple+microstructures+made+of+different+conducting+polymers.">An intermediate-layer lithography method for generating multiple microstructures made of different conducting polymers.</a> Microsystem Technologies. 13 (8), 1175 (2007).</li><li>Madou, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Fundamentals of Microfabrication. , (1995).</li><li>Bustillo, J. M., Howe, R. T., Muller, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surface+micromachining+for+microelectromechanical+systems.">Surface micromachining for microelectromechanical systems.</a> Proceedings of the IEEE. 86, 1552 (1998).</li><li>Liu, X., Luo, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intermediate-layer+lithography+for+producing+metal+micropatterns.">Intermediate-layer lithography for producing metal micropatterns.</a> Journal of Vacuum Science and Technology B. 25, 677 (2007).</li><li>Chakraborty, A., Luo, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiple+conducting+polymer+microwire+sensors.">Multiple conducting polymer microwire sensors.</a> Microsystem Technologies. 15, 1737 (2009).</li><li>Chakraborty, A., Liu, X., Luo, C., Mason, E. C., Weber, A. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Polypyrrole: A new patterning approach and applications. Polypyrrole: Properties, Performance and Applications. , (2011).</li><li>Poddar, R., Luo, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+approach+to+fabricate+a+PPy/p-type+Si+heterojunction.">A novel approach to fabricate a PPy/p-type Si heterojunction.</a> Solid-State Electronics. 50, 1687 (2006).</li><li>Liu, X., Chakraborty, A., Luo, C., Martingale, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Generation of all-polymeric diodes and capacitors using an innovative intermediate-layer lithography. Progress in Solid State Electronics Research. , 127-139 (2008).</li><li>Liu, X., Luo, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fabrication+of+Au+sidewall+micropatterns+using+a+Si-reinforced+PDMS+mold.">Fabrication of Au sidewall micropatterns using a Si-reinforced PDMS mold.</a> Sensors and Actuators A. 152, 96 (2009).</li><li>Liu, X., Chakraborty, A., Luo, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fabrication+of+micropatterns+on+the+sidewalls+of+a+thermal+shape+memory+polystyreme+block.">Fabrication of micropatterns on the sidewalls of a thermal shape memory polystyreme block.</a> Journal of Micromechanics and Microengineering. 20, 095025 (2010).</li><li>Chakraborty, A., Liu, X., Luo, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fabrication+of+micropatterns+on+channel+sidewalls+using+strain-recovery+property+of+a+shape-memory+polymer.">Fabrication of micropatterns on channel sidewalls using strain-recovery property of a shape-memory polymer.</a> Sensors and Actuators A. , (2011).</li><li>Liu, X., Luo, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fabrication+of+supe-hydrophobic+channels.">Fabrication of supe-hydrophobic channels.</a> Journal of Micromechanics and Microengineering. 20, 25029 (2010).</li><li>Luo, C., Meng, F., Liu, X., Guo, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reinforcement+of+PDMS+master+using+an+oxide-coated+silicon+plate.">Reinforcement of PDMS master using an oxide-coated silicon plate.</a> Microelectronics Journal. 37, 5 (2006).</li><li>Luo, C., Garra, J., Schneider, T., White, R., Currie, J., Paranjape, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thermal+ablation+of+PMMA+for+water+release+using+a+microheater.">Thermal ablation of PMMA for water release using a microheater.</a> Sensors and Actuators A. 114, 123 (2004).</li></ol>

No hay conflictos de interés declarado.

Solución de problemas de información: Los puntos críticos en materia de generación de micropatrones individuales y múltiples capas de polímeros conductores y los metales a través del &quot;corte&quot; la operación: (1) La temperatura de relieve asegura la fluidez de la capa intermedia PMMA que genera los mejores resultados. Es aconsejable para iniciar en el límite inferior del intervalo de temperatura y aumentar gradualmente si los resultados deseados no se consiguen. Demasiado alta temperatura...

<table border="1"><tbody><tr><td> Nombre del reactivo </td><td> Empresa </td><td> Número de catálogo </td><td> Comentarios </td></tr><tr><td> PMMA </td><td> Sigma-Aldrich Co. </td><td> 495C9 </td><td> El disolvente es cholorobenzene. Manejar solución PMMA bajo una campana extractora con ventilación adecuada. No respirar los vapores. Consulte la MSDS para obtener instrucciones de manejo seguro. </td></tr><tr><td> PPy </td><td> Sigma-Aldrich Co. </td><td> - </td><td> 5% en peso en agua. Usado como se recibió. </td></tr><tr><td> PEDOT-PSS </td><td> HC Starck Co. </td><td> Baytron P V4 HC </td><td> Propietario solvente. Usado como se recibió. </td></tr><tr><td> Spani </td><td> Sigma-Aldrich Co. </td><td> - </td><td> El agua forma soluble. Usado como se recibió. </td></tr><tr><td> Máquina estampado en caliente </td><td> JenoptikMikrotechnik Co. </td><td> HEX 01/LT </td><td></td></tr><tr><td> Catódica de la máquina </td><td> Cressington Co. </td><td> 208HR </td><td></td></tr><tr><td> FIB máquina </td><td> Zeiss Co. </td><td> FIB 1540 Crossbeam XB </td><td></td></tr><tr><td> Giro revestidor </td><td> Avanza Líneas de investigación Co. </td><td> PWM32-PS-R790 Spinner System </td><td></td></tr><tr><td> RIE máquina </td><td> Técnicas MicroRIE Co. </td><td> - </td><td></td></tr><tr><td> CIs </td><td> Shipley Co. </td><td> S1813 </td><td></td></tr><tr><td> PDMS </td><td> Dow Corning </td><td> Sylgard 184 kit de silicona de elastómero </td><td></td></tr><tr><td> Polietileno de alta densidad hoja de </td><td> Incorporar plástico EE.UU. </td><td> - </td><td></td></tr><tr><td> Hoja de PMMA </td><td> Cyro Co. </td><td> - </td><td></td></tr><tr><td> A doble cara adhesive la cinta </td><td> Scotch Co. </td><td> - </td><td></td></tr><tr><td> Un solo lado de cinta </td><td> Delphon Co. </td><td> Ultratape # 1310 </td><td></td></tr><tr><td> Micropipetas de vidrio </td><td> FHC Co. </td><td> 30-30-1 </td><td></td></tr><tr><td> Recortar </td><td> Office Depot Co. </td><td> Clip de pinza </td><td></td></tr><tr><td> Humidificador </td><td> Vicks Co. </td><td> Humidificador sin Filtro </td><td></td></tr></tbody></table>

micropunching lithography for generating micro- and submicron-patterns on polymer substrates

Polímeros conductores han atraído gran atención desde el descubrimiento de alta conductividad en poliacetileno dopado en 1977 1. Ofrecen las ventajas de bajo peso, fácil adaptación de las propiedades y una amplia gama de aplicaciones de 2,3. Debido a la sensibilidad de los polímeros conductores a las condiciones ambientales (por ejemplo, el aire, las soluciones de oxígeno, la humedad, altas temperaturas y químicos), las técnicas litográficas presentan importantes desafíos técnicos para trabajar con estos materiales 4. Por ejemplo, los actuales métodos fotolitográficos, tales como ultra-violeta (UV), no son adecuados para modelar los polímeros conductores debido a la implicación de los procesos de grabado húmedo y / o en seco en estos métodos. Además, los actuales micro / nanosistemas principalmente tienen una forma plana 5,6. Una capa de estructuras se construye sobre las superficies superiores de otra capa de características fabricadas. Varias capas de estas estructuras se apilan para formar numerosos dispositivos sobreun sustrato común. Las superficies laterales de las microestructuras no se han utilizado en la construcción de dispositivos. Por otro lado, los patrones de las paredes laterales podrían ser utilizados, por ejemplo, para construir circuitos en 3-D, modificar los canales fluídicos y el crecimiento directo horizontal de nanocables y nanotubos. Un método macropunching se ha aplicado en la industria manufacturera para crear macropatrones en una chapa metálica de más de cien años. Motivados por este enfoque, hemos desarrollado un método de litografía micropunching (MPL) para superar los obstáculos de los patrones polímeros conductores y la generación de los patrones de las paredes laterales. Al igual que el método macropunching, la MPL también incluye dos operaciones (Fig. 1): (i) de corte, y de dibujo (ii). El &quot;corte&quot; la operación fue aplicada a tres patrones de polímeros conductores 4, polipirrol (PPy), poli (3,4-ethylenedioxythiophen)-poli (4-estirenosulfonato) (PEDOT) y la polianilina (PANI). Se emplea también para crear microestructuras al 7. Las microestructuras fabricadas de polímeros conductores han sido utilizados como humedad 8, 8 química, y la glucosa sensores 9. Microestructuras combinados de Al y polímeros conductores han sido empleados para fabricar capacitores y heterouniones diversos 9,10,11. El &quot;corte&quot;, la operación también se aplicó para generar submicrónicas de patrones, como la 100 - y 500 nm de ancho líneas de PPy, así como de 100 nm de ancho-cables Au. El &quot;dibujo&quot; la operación fue empleada para dos aplicaciones: (i) producen patrones de Au laterales de polietileno de alta densidad (HDPE) de canales que podrían ser utilizados para la construcción de microsistemas 3D 12,13,14, y (ii) fabricar polidimetilsiloxano (PDMS) micropilares sobre sustratos de HDPE para aumentar el ángulo de contacto del canal 15.

Watch this Scientific Journal Video about Micropunching Lithography for Generating Micro- and Submicron-patterns on Polymer Substrates at JoVE.com

Micropunching Lithography for Generating Micro- and Submicron-patterns on Polymer Substrates

Un enfoque litografía micropunching se ha desarrollado para generar micro y submicrónicas patrones de en la parte superior, lateral y las superficies inferiores de substratos de polímeros. Supera los obstáculos de los patrones de polímeros conductores y la generación de los patrones de las paredes laterales. Este método permite una fabricación rápida de características múltiples y está libre de la química agresiva.

Micropunching litografía para la generación de microempresas y patrones de submicrónicas de sustratos poliméricos

Conducting polymers have attracted great attention since the discovery of high conductivity in doped polyacetylene in 19771. They offer the advantages of ...

micropunching-lithography-for-generating-micro-submicron-patterns-on

Research

JoVE Journal

Engineering

15.1K vistas.  University of Texas at Arlington. Un enfoque litografía micropunching se ha desarrollado para generar micro y submicrónicas patrones de en la parte superior, lateral y las superficies inferiores de substratos de polímeros. Supera los obstáculos de los patrones de polímeros conductores y la generación de los patrones de las paredes laterales. Este método permite una fabricación rápida de características múltiples y está libre de la química agresiva.

Video: Micropunching Lithography for Generating Micro- and Submicron-patterns on Polymer Substrates

Ultrahigh Density Array of Vertically Aligned Small-molecular Organic Nanowires on Arbitrary Substrates

In recent years &pi;-conjugated organic semiconductors have emerged as the active material in a number of diverse applications including large-area, low-cost displays, photovoltaics, printable and flexible electronics and organic spin valves. Organics allow (a) low-cost, low-temperature processing and (b) molecular-level design of electronic, optical and spin transport characteristics. Such features are not readily available for mainstream inorganic semiconductors, which have enabled organics to carve a niche in the silicon-dominated electronics market. The first generation of organic-based devices has focused on thin film geometries, grown by physical vapor deposition or solution processing. However, it has been realized that organic nanostructures can be used to enhance performance of above-mentioned applications and significant effort has been invested in exploring methods for organic nanostructure fabrication.	
A particularly interesting class of organic nanostructures is the one in which vertically oriented organic nanowires, nanorods or nanotubes are organized in a well-regimented, high-density array. Such structures are highly versatile and are ideal morphological architectures for various applications such as chemical sensors, split-dipole nanoantennas, photovoltaic devices with radially heterostructured "core-shell" nanowires, and memory devices with a cross-point geometry. Such architecture is generally realized by a template-directed approach. In the past this method has been used to grow metal and inorganic semiconductor nanowire arrays. More recently &pi;-conjugated polymer nanowires have been grown within nanoporous templates. However, these approaches have had limited success in growing nanowires of technologically important &pi;-conjugated small molecular weight organics, such as tris-8-hydroxyquinoline aluminum (Alq3), rubrene and methanofullerenes, which are commonly used in diverse areas including organic displays, photovoltaics, thin film transistors and spintronics.	
Recently we have been able to address the above-mentioned issue by employing a novel "centrifugation-assisted" approach. This method therefore broadens the spectrum of organic materials that can be patterned in a vertically ordered nanowire array. Due to the technological importance of Alq3, rubrene and methanofullerenes, our method can be used to explore how the nanostructuring of these materials affects the performance of aforementioned organic devices. The purpose of this article is to describe the technical details of the above-mentioned protocol, demonstrate how this process can be extended to grow small-molecular organic nanowires on arbitrary substrates and finally, to discuss the critical steps, limitations, possible modifications, trouble-shooting and future applications.

We report a simple method for fabricating an ultrahigh density array of vertically ordered small-molecular organic nanowires. This method allows for synthesis of complex heterostructured hybrid nanowire geometries, which can be inexpensively grown on arbitrary substrates. These structures have potential applications in organic electronics, optoelectronics, chemical sensing, photovoltaics and spintronics.

Ultra Alta Densidad conjunto de nanocables orgánicos pequeña moleculares verticalmente alineados sobre sustratos arbitrarias

In  recent years &pi;-conjugated  organic semiconductors have emerged as the active material in a number of  diverse applications including large-area, ...

Investigación

Ingeniería

Preparation and Friction Force Microscopy Measurements of Immiscible, Opposing Polymer Brushes

Solvated polymer brushes are well known to lubricate high-pressure contacts, because they can sustain a positive normal load while maintaining low friction at the interface. Nevertheless, these systems can be sensitive to wear due to interdigitation of the opposing brushes. In a recent publication, we have shown via molecular dynamics simulations and atomic force microscopy experiments, that using an immiscible polymer brush system terminating the substrate and the slider surfaces, respectively, can eliminate such interdigitation. As a consequence, wear in the contacts is reduced. Moreover, the friction force is two orders of magnitude lower compared to traditional miscible polymer brush systems. This newly proposed system therefore holds great potential for application in industry. Here, the methodology to construct an immiscible polymer brush system of two different brushes each solvated by their own preferred solvent is presented. The procedure how to graft poly(N-isopropylacrylamide) (PNIPAM) from a flat surface and poly(methyl methacrylate) (PMMA) from an atomic force microscopy (AFM) colloidal probe is described. PNIPAM is solvated in water and PMMA in acetophenone. Via friction force AFM measurements, it is shown that the friction for this system is indeed reduced by two orders of magnitude compared to the miscible system of PMMA on PMMA solvated in acetophenone.

The methodology to perform friction force microscopy experiments for contacting brushes is presented: Two polymer brushes that are grafted from (a) substrates and (b) colloidal probes are slid to show that, by using two contacting immiscible brush systems, friction in sliding contacts is reduced compared to miscible brush systems.

Preparación y Fricción Fuerza Microscopía mediciones de inmiscibles, opuestos polímero Cepillos

Solvated polymer brushes are well known to lubricate high-pressure contacts, because they can sustain a positive normal load while maintaining low ...

Adsorption Device Based on a Langatate Crystal Microbalance for High Temperature High Pressure Gas Adsorption in Zeolite H-ZSM-5

We present a high-temperature and high-pressure gas adsorption measurement device based on a high-frequency oscillating microbalance (5 MHz langatate crystal microbalance, LCM) and its use for gas adsorption measurements in zeolite H-ZSM-5. Prior to the adsorption measurements, zeolite H-ZSM-5 crystals were synthesized on the gold electrode in the center of the LCM, without covering the connection points of the gold electrodes to the oscillator, by the steam-assisted crystallization (SAC) method, so that the zeolite crystals remain attached to the oscillating microbalance while keeping good electroconductivity of the LCM during the adsorption measurements. Compared to a conventional quartz crystal microbalance (QCM) which is limited to temperatures below 80 &#176;C, the LCM can realize the adsorption measurements in principle at temperatures as high as 200-300 &#176;C (i.e., at or close to the reaction temperature of the target application of one-stage DME synthesis from the synthesis gas), owing to the absence of crystalline-phase transitions up to its melting point (1,470 &#176;C). The system was applied to investigate the adsorption of CO2, H2O, methanol and dimethyl ether (DME), each in the gas phase, on zeolite H-ZSM-5 in the temperature and pressure range of 50-150 &#176;C and 0-18 bar, respectively. The results showed that the adsorption isotherms of these gases in H-ZSM-5 can be well fitted by Langmuir-type adsorption isotherms. Furthermore, the determined adsorption parameters, i.e., adsorption capacities, adsorption enthalpies, and adsorption entropies, compare well to literature data. In this work, the results for CO2 are shown as an example.

A protocol for high-temperature and high-pressure gas adsorption measurements on zeolite H-ZSM-5 using an adsorption measurement device based on a langatate crystal microbalance is presented. Prior to the adsorption measurements, the synthesis of zeolite H-ZSM-5 on the langatate crystal microbalance sensor by the steam-assisted crystallization (SAC) method is demonstrated.

Dispositivo de adsorción Basado en una microbalanza de cristal Langatate de alta temperatura y alta presión de adsorción de gas en la zeolita H-ZSM-5

We present a high-temperature and high-pressure gas adsorption measurement device based on a high-frequency oscillating microbalance (5 MHz langatate ...

Morphology Control for Fully Printable Organic&#8211;Inorganic Bulk-heterojunction Solar Cells Based on a Ti-alkoxide and Semiconducting Polymer

The photoactive layer of a typical organic thin-film bulk-heterojunction (BHJ) solar cell commonly uses fullerene derivatives as the electron-accepting material. However, fullerene derivatives are air-sensitive; therefore, air-stable material is needed as an alternative. In the present study, we propose and describe the properties of Ti-alkoxide as an alternative electron-accepting material to fullerene derivatives to create highly air-stable BHJ solar cells. It is well-known that controlling the morphology in the photoactive layer, which is constructed with fullerene derivatives as the electron acceptor, is important for obtaining a high overall efficiency through the solvent method. The conventional solvent method is useful for high-solubility materials, such as fullerene derivatives. However, for Ti-alkoxides, the conventional solvent method is insufficient, because they only dissolve in specific solvents. Here, we demonstrate a new approach to morphology control that uses the molecular bulkiness of Ti-alkoxides without the conventional solvent method. That is, this method is one approach to obtain highly efficient, air-stable, organic-inorganic bulk-heterojunction solar cells.

Morphology Control for Fully Printable Organic&amp;#8211;Inorganic Bulk-heterojunction Solar Cells Based on a Ti-alkoxide and Semiconducting Polymer

A method for fully printable, fullerene-free, highly air-stable, bulk-heterojunction solar cells based on Ti alkoxides as the electron acceptor and the electron-donating polymer fabrication is described here. Moreover, a method for controlling the morphology of the photoactive layer through the molecular bulkiness of the Ti-alkoxide units is reported.

Control de la morfología de las células solares a granel-heterounión orgánica-inorgánica completamente para imprimir Sobre la base de un Ti-alcóxido y semiconductores de polímero

The photoactive layer of a typical organic thin-film bulk-heterojunction (BHJ) solar cell commonly uses fullerene derivatives as the electron-accepting ...

Fabrication of Polymer Microspheres for Optical Resonator and Laser Applications

This paper describes three methods of preparing fluorescent microspheres comprising &#960;-conjugated or non-conjugated polymers: vapor diffusion, interface precipitation, and mini-emulsion. In all methods, well-defined, micrometer-sized spheres are obtained from a self-assembling process in solution. The vapor diffusion method can result in spheres with the highest sphericity and surface smoothness, yet the types of the polymers able to form these spheres are limited. On the other hand, in the mini-emulsion method, microspheres can be made from various types of polymers, even from highly crystalline polymers with coplanar, &#960;-conjugated backbones. The photoluminescent (PL) properties from single isolated microspheres are unusual: the PL is confined inside the spheres, propagates at the circumference of the spheres via the total internal reflection at the polymer/air interface, and self-interferes to show sharp and periodic resonant PL lines. These resonating modes are so-called "whispering gallery modes" (WGMs). This work demonstrates how to measure WGM PL from single isolated spheres using the micro-photoluminescence (&#181;-PL) technique. In this technique, a focused laser beam irradiates a single microsphere, and the luminescence is detected by a spectrometer. A micromanipulation technique is then used to connect the microspheres one by one and to demonstrate the intersphere PL propagation and color conversion from coupled microspheres upon excitation at the perimeter of one sphere and detection of PL from the other microsphere. These techniques, &#181;-PL and micromanipulation, are useful for experiments on micro-optic application using polymer materials.

Protocols for the synthesis of microspheres from polymers, the manipulation of microspheres, and micro-photoluminescence measurements are presented.

Fabricación de microesferas de polímero para aplicaciones de resonador óptico y láser

This paper describes three methods of preparing fluorescent microspheres comprising &#960;-conjugated or non-conjugated polymers: vapor diffusion, ...

Radio Frequency Magnetron Sputtering of GdBa2Cu3O7&#8722;&#948;/ La0.67Sr0.33MnO3 Quasi-bilayer Films on SrTiO3 (STO) Single-crystal Substrates

Here, we demonstrate a method of coating ferromagnetic La0.67Sr0.33MnO3 (LSMO) nanoparticles on (001) SrTiO3 (STO) single-crystal substrates by radio frequency (RF) magnetron sputtering. LSMO nanoparticles were deposited with diameters from 10 to 20 nm and heights between 20 and 50 nm. At the same time, (Gd) Ba2Cu3O7&#8722;&#948; ((Gd) BCO) films were fabricated on both undecorated and LSMO nanoparticle decorated STO substrates using RF magnetron sputtering. This report also describes the properties of GdBa2Cu3O7&#8722;&#948;/ La0.67Sr0.33MnO3 quasi-bilayer films structures (e.g., crystalline phase, morphology, chemical composition); magnetization, magneto-transport, and superconducting transport properties were also evaluated.

Radio Frequency Magnetron Sputtering of GdBa2Cu3O7ÃƒÂ¢Ã‹â€ &#039;ÃƒÅ½ ´/ La0.67Sr0.33MnO3 Quasi-bilayer Films on SrTiO3 STO Single-crystal Substrates

Here, we present a protocol to grow LSMO nanoparticles and (Gd) BCO films on (001) SrTiO3 (STO) single-crystal substrates by radio frequency (RF)-sputtering.

Radio frecuencia de magnetrón Sputtering de GdBa2Cu3O7−δ/ La0.67Films Sr0.33MnO3 cuasi-bicapa sobre sustratos de monocristal SrTiO3 (STO)

Here, we demonstrate a method of coating ferromagnetic La0.67Sr0.33MnO3 (LSMO) nanoparticles on (001) SrTiO3 (STO) single-crystal substrates by radio ...

Single-Digit Nanometer Electron-Beam Lithography with an Aberration-Corrected Scanning Transmission Electron Microscope

We demonstrate extension of electron-beam lithography using conventional resists and pattern transfer processes to single-digit nanometer dimensions by employing an aberration-corrected scanning transmission electron microscope as the exposure tool. Here, we present results of single-digit nanometer patterning of two widely used electron-beam resists: poly (methyl methacrylate) and hydrogen silsesquioxane. The method achieves sub-5 nanometer features in poly (methyl methacrylate) and sub-10 nanometer resolution in hydrogen silsesquioxane. High-fidelity transfer of these patterns into target materials of choice can be performed using metal lift-off, plasma etch, and resist infiltration with organometallics.

We use an aberration-corrected scanning transmission electron microscope to define single-digit nanometer patterns in two widely-used electron-beam resists: poly (methyl methacrylate) and hydrogen silsesquioxane. Resist patterns can be replicated in target materials of choice with single-digit nanometer fidelity using liftoff, plasma etching, and resist infiltration by organometallics.

Solo dígito nanómetros litografía de haz de electrones con una aberración-corregido exploración microscopio electrónico de transmisión

We demonstrate extension of electron-beam lithography using conventional resists and pattern transfer processes to single-digit nanometer dimensions by ...

Generating Lap Joints Via Friction Stir Spot Welding on DP780 Steel

Friction stir spot welding (FSSW), a derivative of friction stir welding (FSW), is a solid-state welding technique that was developed in 1991. An industry application was found in the automotive industry in 2003 for the aluminum alloy that was used in the rear doors of automobiles. Friction stir spot welding is mostly used in Al alloys to create lap joints. The benefits of friction stir spot welding include a nearly 80% melting temperature that lowers the thermal deformation welds without splashing compared to resistance spot welding. Friction stir spot welding includes 3 steps: plunging, stirring, and retraction. In the present study, other materials including high strength steel are also used in the friction stir welding method to create joints. DP780, whose traditional welding process involves the use of resistance spot welding, is one of several high strength steel materials used in the automotive industry. In this paper, DP780 was used for friction stir spot welding, and its microstructure and microhardness were measured. The microstructure data showed that there was a fusion zone with fine grain and a heat effect zone with island martensite. The microhardness results indicated that the center zone exhibited a greater degree of hardness compared with the base metal. All data indicated that the friction stir spot welding used in dual phase steel 780 can create a good lap joint. In the future, friction stir spot welding can be used in high-strength steel welding applied in industrial manufacturing processes.

Here, we present a friction stir spot welding (FSSW) protocol on dual phase 780 steel. A tool pin with high-speed rotation generates heat from friction to soften the material, and then, the pin plunges into 2 sheet joints to create the lap joint.

Generación de juntas de vuelta a través de soldadura por punto de agitación por fricción en acero DP780

Friction stir spot welding (FSSW), a derivative of friction stir welding (FSW), is a solid-state welding technique that was developed in 1991. An industry ...

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.

Procedimiento para la transferencia de películas de polímeros a sustratos porosos con defectos minimizados

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

In Situ Transmission Electron Microscopy with Biasing and Fabrication of Asymmetric Crossbars Based on Mixed-Phased a-VOx

Resistive switching crossbar architecture is highly desired in the field of digital memories due to low cost and high-density benefits. Different materials show variability in resistive switching properties due to the intrinsic nature of the material used, leading to discrepancies in the field because of underlying operation mechanisms. This highlights a need for a reliable technique to understand mechanisms using nanostructural observations. This protocol explains a detailed process and methodology of in&#160;situ nanostructural analysis as a result of electrical biasing using transmission electron microscopy (TEM). It provides visual and reliable evidence of underlying nanostructural changes in real time memory operations. Also included is the methodology of fabrication and electrical characterizations for asymmetric crossbar structures incorporating amorphous vanadium oxide. The protocol explained here for vanadium oxide films can be easily extended to any other materials in a metal-dielectric-metal sandwiched structure. Resistive switching crossbars are predicted to serve the programmable logic and neuromorphic circuits for next-generation memory devices, given the understanding of the operation mechanisms. This protocol reveals the switching mechanism in a reliable, timely, and cost-effective way in any type of resistive switching materials, and thereby predicts the device&#39;s applicability.

In Situ Transmission Electron Microscopy with Biasing and Fabrication of Asymmetric Crossbars Based on Mixed-Phased a-VOx

Presented here is a protocol for analyzing nanostructural changes during in&#160;situ biasing with transmission electron microscopy (TEM) for a stacked metal-insulator-metal structure. It has significant applications in resistive switching crossbars for the next generation of programmable logic circuits and neuromimicking hardware, to reveal their underlying operation mechanisms and practical applicability.

Microscopía electrónica de transmisión in situ con sesgo y fabricación de travesaños asimétricos basados en fase mixta a-VOx