Ecuador se acerca al mundo de la

nanotecnología

DICIEMBRE 4, 2012

"Han pasado siete décadas desde que los humanos vieron por primera vez una computadora, un equipo electrónico que no solo ocupaba un cuarto entero sino que era difícil de maniobrar. Ahora, en el 2012 y con una evolución continua no es sorprendente observar pequeñas pantallas táctiles que guardan información y se acoplan a la ergonomía humana. A este proceso de eficiencia, optimización y simplicidad se le llama nanotecnología, una rama científica que pretende modificar la materia a una escala diminuta, es decir, átomo por átomo: una partícula de un nanómetro (nm) mide la millonésima parte de un milímetro; en números: 0,000000001 metros.

Según Javier Torres, catedrático e investigador de la Universidad San Francisco, la nanotecnología permite a la humanidad ser más eficiente y rápida. El francés Frederic Chandezon, miembro de la Comisión de Energía Atómica y Energía Renovable (CEA), añade que al elaborar objetos más pequeños se aumenta la potencialidad de un producto y se logra un objeto más ligero. ¿Cómo? A través de una mezcla de partículas que logran un material liviano, pero resistente. Al hacerlo, “los científicos se sumergen en un mundo exótico y desconocido”, dice César Costa, docente del Departamento de Física de la Escuela Politécnica Nacional (EPN), porque la nanotecnología está dentro del mundo cuántico, donde los átomos y las moléculas son diferentes a lo que se conoce actualmente. “Como investigadores es fácil utilizar pedazos grandes, pero ir al límite y tomar la base fundamental implica precisión y esfuerzo”. La nanotecnología pretende entender cómo está constituida la materia a nivel atómico para saber cómo se puede modificar las interacciones de los elementos.

Desde hace dos años, estos investigadores ecuatorianos junto con docentes de la UTPL, Espoch, Espol, ESPE y otras instituciones, crearon el Grupo Ecuatoriano para el Estudio Experimental y Teórico de Nanosistemas (GETNano). El trabajo de esta organización académica permitió que la semana pasada se realizara la segunda edición de la “Escuela Nano Andes”, apoyada por la Embajada francesa y que tuvo lugar por primera vez en Quito. Por el momento, los avances en esta rama en el país son teóricos. Los docentes están instruyendo a sus alumnos nacionales y extranjeros para desarrollar proyectos nanos. Joana Bustamante, egresada de Ingeniería Química de la UTPL, y sus demás compañeros tratan de comprender el procedimiento para elaborar celdas solares o sensores nanos. Bustamante detalla que ingresó a estudiar ingeniería porque no encontró una carrera de ciencias puras."

Torres aclara que la nanotecnología no es una carrera sino que es la unión de aptitudes y especialidades científicas, en que convergen físicos, químicos, electrónicos, matemáticos… Un área totalmente multidisciplinaria. La estudiante de GETNano comenta que en el país todavía falta una cultura que apoye el desarrollo científico y que proporcione infraestructura. Aunque GETNano cuenta con laboratorios de experimentación que son adaptados en las universidades, Costa comenta que esto es insuficiente si se quiere competir y lograr una producción rentable a través de nanotecnología.

 http://www.nanodepot.mx/nanoblog/

Nanocarros

Synthesis and Single-Molecule Imaging of Highly Mobile Adamantane-Wheeled Nanocars

• pubs.acs.org
• Author Of
• November 27th, 2012

The synthesis and single-molecule imaging of two inherently fluorescent nanocars equipped with adamantane wheels is reported. The nanocars were imaged using 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) as the chromophore, which was rigidly incorporated into the nanocar chassis via Sonogashira cross-coupling chemistry that permitted the synthesis of nanocars having different geometries. In particular, studied here were four- and three-wheeled nanocars with adamantane wheels. It was found that, for the four-wheeled nanocar, the percentage of moving nanocars and the diffusion constant show a significant improvement overp-carborane-wheeled nanocars with the same chassis. The three-wheeled nanocar showed only limited mobility due to its geometry. These results are consistent with a requisite wheel-like rolling motion. We furthermore developed a model that relates the percentage of moving nanocars in single-molecule experiments with the diffusion constant. The excellent agreement between the model and the new results presented here as well as previous single-molecule studies of fluorescent nanocars yields an improved understanding of motion in these molecular machines.

México en Nanotecnologia platica con la Dra. Julia Tagüeña Parga.

¿Tiene México posibilidad en nanotecnología?

Ademas de las revoluciones que todos conocemos de México, existen las revoluciones tecnológicas que siempre nos rodearon. Ahora tenemos la oportunidad de resaltar y entrar en esta nueva revolución tecnológica que es la nanotecnologia. Estamos justo a tiempo.

Es una entrevista a La Dra. Julia Tagüeña Parga física egresada de la Facultad de Ciencias de la UNAM. Obtuvo el doctorado sobre Física del Estado Sólido en la Universidad de Oxford, Inglaterra. Donde nos explica lo nano en general y la visión de sobre México en estos temas. Entendible de manera muy general.

http://www.youtube.com/watch?v=6gp0fu6D-NU

Ejemplo de nanotecnologia en textiles con materiales hydrofobicos

Un par de vídeos con ejemplos de nanotecnologia en textiles muy ilustrativos.

http://www.youtube.com/watch?v=0q1ZnuVZzC4

http://www.youtube.com/watch?v=aLTvhbuye24

Nanotubo de grafeno hybrido

Siete anillos de átomos (en rojo) en la transición de grafeno  a nanotubos para hacer un material híbrido nuevo de la Universidad Rice de un conductor transparente.El híbrido puede ser el mejor material de interfaz de electrodo posible para el almacenamiento de energía y muchos otros usos de la electrónica.

Los bosques de nanotubos crecen directamente del grafeno en la Universidad Rice es un material híbrido, con una superficie enorme, posiblemente el mejor material para supercondensadores y otras aplicaciones eléctricas.

Credit: Tour Group/Rice University
http://phys.org/news/2012-11-james-bond-graphene-nanotube-hybrid.html

La nanotecnologia en la mejora dental

Una buena sonrisa no solo es muy atractiva, sino que indica un buen alineamiento dental lo que propicia no solo belleza estética sino una mejor digestión al momento de moler la comida con los dientes.

Los ortodoncias utilizan brackets para hacer sus correcciones dentales, por lo regular los brackets están hechos de metal, porcelana blanca o de plástico transparente, se espera que con la nanotecnologia se utilicen mejores materiales ya que los anteriores presentan ciertas incomodidades tales como propiciar raspones en el área bucal.

Los investigadores de la Universidad de Carlos III de Madrid (UC3M), junto con una empresa privada, han patentado un proceso nuevo y han producido un nuevo material que aumenta la mecánica, así como la resistencia a la fricción, con lo que se mantiene la transparencia de los brackets hechos de polímeros con la ayuda de nanoparticulas de alúmia; Ademas de ser biocompatible contiene propiedades que permiten tanto la mejora del tratamiento como el del portador.




http://phys.org/news/2012-11-nanotechnology.html

Químicos de la Universidad de Massachusetts Amherst desarrollan una matriz de sensores similar a una nariz para "oler" los diagnósticos de cáncer

En la lucha contra el cáncer, conocer la identidad exacta del enemigo es fundamental para el diagnóstico y el tratamiento, especialmente en los cánceres metastásicos, aquellos que se extienden entre los órganos y tejidos. Ahora, los químicos dirigidos por Vincent Rotello en la Universidad de Massachusetts Amherst han desarrollado un método rápido y sensible para detectar niveles microscópicos de muchos tipos diferentes de células metastásicas en los tejidos vivos. Los resultados aparecen en la edición actual de la revista ACS Nano.

En un modelo preclínico de metástasis de cáncer de pulmón no microcítico en ratones desarrollado por Frank Jirik y sus colegas de la Universidad de Calgary, el equipo de Rotello de la Universidad de Massachusetts Amherst utiliza un sistema de sensores matriciales de nanopartículas de oro y proteínas para "oler" los diferentes tipos de cáncer de un modo similar al que una nariz identifica y recuerda diferentes olores. El nuevo trabajo se basa en un desarrollo anterior de Rotello y sus colegas, una matriz de nanopartículas y polímeros que actúa como una "nariz química" capaz de diferenciar entre las células normales y las cancerosas. 


Fuente: UMass Amherst

¿Mito o realidad?

"Destruir la células del cáncer en diez días. Esta afirmación, que parece más un eslogan de algún producto para perder peso que un importante avance es lo que aseguran científicos japoneses de la Universidad de Sanidad e Higiene que han desarrollado un tratamiento capaz destruir las células del cáncer en tan sólo diez días.

El avance es esperanzador y sorprendentemente novedoso, pues la nanotecnología tiene un papel fundamental, de hecho, estamos ante la primera utilización del famoso “nanotubo de carbono” en una aplicación médica.

El tratamiento por tanto, es combinado, a la ingesta de un fármaco se le añade la tecnología láser para mejorar su rendimiento se utiliza el citado nanotubo de carbono, que bajo el microscopio, representa una sustancia en forma de polvo parecida a una fibra extrafina.

Este nanotubo ayuda al fármaco a llegar más eficazmente hasta la célula. Los experimentos con ratones mostraron que las células del cáncer sometidas a un tratamiento con rayos láser durante 15 minutos diarios dejaban de existir dentro de diez días.

El paso siguiente será, naturalmente, probar su método en animales de tamaño grande, y después, proceder al tratamiento de las enfermedades oncológicas en las personas."

Son incontables las personas que buscan trascender en el mundo de la medicina, al curar una enfermedad maligna, tal como el cancer. cabe mencionar que la nanotecnlogía podría brindar una cura a la misma. Los avances propuestos son prometedores sin embargo en mi opinion, se deberia tener mayor conocimiento de temas relacionados a la nanomedicina.

El farmaco podria llegar facilmente a la célula dañada y asi curar la enfermedad, citando al autor, la prueba y uso de este metodo tardaria almenos 10 años ya que aun debe ser probado en animales de mayor tamaño y sistemas similares a los nuestros.

http://www.novaciencia.com/category/nanotecnologia/

Mercado prometedos para la industria de la Nanotecnología

En los próximos años, la nanotecnología está llamada a desempeñar un papel fundamental en diversos segmentos de la industria. La evolución de esta tecnología ha influido ya en un gran número de segmentos industriales y la actividad económica generada a partir de ella ha sido de gran magnitud y amplio alcance. Los productos basados en nanotecnología, que han tenido un enorme impacto en casi todos los sectores industriales, están llegando ahora al mercado de los consumidores con gran fuerza.

De acuerdo con las conclusiones del último informe, el aumento de las aplicaciones de la tecnología en sectores como la electrónica, la cosmética y la defensa, impulsaría el crecimiento del mercado mundial de la nanotecnología, que se prevé que crecerá a una tasa compuesta anual de alrededor del 19% durante el período 2011-2014.

De acuerdo con el informe "Nanotechnology Market Forecast to 2014", las compañías del campo de la electrónica están buscando nuevas formas de incorporar la nanotecnología en productos de consumo como los equipos de música y los teléfonos móviles, con el fin de mejorar sus capacidades de procesamiento. Del mismo modo, la tecnología podría ayudar a mejorar los cosméticos cambiando sus propiedades físicas. También se observó que el uso de la nanotecnología en tecnologías de defensa proporciona un mejor rendimiento a menor coste. Además, la tecnología en ciernes ha revolucionado el cuidado dental, dado que disminuye el tiempo de cicatrización y mejora la integración ósea en los implantes dentales.

El informe analiza en detalle estas áreas de aplicación y las tendencias clave del mercado. A pesar de que los nanomateriales seguirán dominando el mercado de la nanotecnología en los próximos años, se estima que los nanodispositivos, en los que se incluyen las herramientas de nanolitografía para la fabricación de la próxima generación de semiconductores, crecerán a un ritmo mucho más rápido que los nanomateriales en un futuro próximo. El análisis crucial a nivel nacional, incluido en esta exhaustiva investigación, identificó que los EE.UU. es el mercado de nanotecnología más destacado del mundo y seguirá disfrutando de la mayor porción de la industria global.

Además de esto, el informe trata la financiación mundial de I + D en nanotecnología, incluyendo la separación de financiación empresarial, pública y de capital riesgo, junto con su pronóstico. También se ha tratado el análisis regional de los diferentes tipos de financiación para el presente y el futuro. El informe abarca incluso un análisis a nivel nacional de la financiación de I + D para proporcionar un conocimiento profundo acerca de las inversiones relacionadas con la nanotecnología.

Con el fin de ofrecer una visión equilibrada del mercado mundial de la nanotecnología a los clientes, el informe también incluye los perfiles de los principales participantes del sector, como Altair, Nanophase Tech y Nanosys, entre otros. En general, el objetivo del estudio es ayudar a los clientes a conocer las perspectivas del sector y tomar decisiones de inversión en función de ellas.


Fuentes: Avances en nanotecnología 

Avances en tratamientos del cáncer.

Metal nanoparticles may improve cancer treatment.
November 30, 2012 

The research team developed a detector to measure the radiation dose in three dimensions. Research led by RMIT University has shown that cheap, non-toxic nanoparticles can enhance radiotherapy treatments for cancer. An international team of researchers led by RMIT has investigated alternatives to gold nanoparticles, which have been shown to concentrate radiation used to treat cancer but are highly expensive and mildly toxic. Doctoral researcher Mamdooh Alqathami said the team had identified bismuth as an ideal option, with tests showing that enhancing radiotherapy by using nanoparticles containing the heavy metal almost doubled the dose of radiation to surrounding cancerous tissue. "By enhancing radiation in the tumour, doctors may be able to decrease the initial dose of radiotherapy, which will hopefully result in fewer side effects for the patient while having the same impact on the cancer," Mr Alqathami, a researcher in the School of Medical Sciences, said. "Metal nanoparticles have shown promise in improving the efficacy of radiotherapy but there is a need to find cheaper and safer alternatives for therapeutic use. "Bismuth-based nanoparticles are an attractive option as they cost only a few dollars per gram, compared with thousands of dollars a gram for gold, and they are non-toxic, reducing any side effects from potential treatments. "While further work needs to be done before our findings can be implemented into conventional cancer treatments, this is an exciting advance that gives us a promising focus for ongoing research." Mr Alqathami collaborated with researchers from RMIT's Health Innovations Research Institute, the University of Melbourne, the University of Surrey (UK) and the Institute of Cancer Research (UK) on the study. To test the efficacy of bismuth, Mr Alqathami placed the nanoparticles inside a detector developed by his team to measure the radiation dose in three dimensions. The sample and detector was exposed to radiation that would normally be used to treat cancers. The final dose delivered was then compared with normal treatments, showing the bismuth-based nanoparticles increased the radiation dose by 90 per cent. The team is planning further tests to validate the findings and fully understand the dosage increase, to enable the findings to be implemented in cancer treatment. This research was presented at the International Conference on 3D Radiation Dosimetery recently held in Sydney. Provided by RMIT University 

Read more at: http://phys.org/news/2012-11-metal-nanoparticles-cancer-treatment.html#jCp

Fullerenos como contenedores

Molecules ‘quantum rattle’ in buckyball cage

• futurity.org
• Emma Thorne-nottingham
• August 29th, 2012
• view original

"Under these conditions, the confined molecules reveal a wave-like nature and behave according to the laws of quantum mechanics," says University of Southampton Professor Malcolm Levitt. "Apart from their intrinsic interest, we expect that the special properties of these materials will lead to a variety of applications, such as new ways to brighten the images of MRI scans, and new types of computer memory."Photo by: Credit: Hajv1/Wikimedia Commons

The nano-meter sized cavity of the hollow spherical C60 Buckminsterfullerene—or buckyball—effectively creates a “nanolaboratory,” allowing detailed study of the quantum mechanical principles that determine the motion of the caged molecule, including the mysterious wave-like behavior that is a fundamental property of all matter.

Experiments by the international team of researchers, including physicists from the University of Nottingham, have revealed the wave-like behavior and show how the imprisoned H2 and H2O molecules ‘quantum rattle’ in their cage.

Straight from the Source

Read the original study

DOI: 10.1073/pnas.1210790109

Professor Tony Horsewill of the School of Physics and Astronomy says: “For me a lot of the motivation for carrying out this investigation came from the sheer pleasure of studying such a unique and beautiful molecule and teasing out the fascinating insights it gave into the fundamentals of quantum molecular dynamics. Intellectually, it’s been hugely enjoyable.

“However, as with any blue-skies research initiative there is always the promise of new, often unforeseen, applications. Indeed, in the case of water molecules inside buckyballs we have a guest molecule that possesses an electric dipole moment and the collaboration is already investigating its use in molecular electronics, including as an innovative component of a molecular transistor.”

The research has recently been published in Proceedings of the National Academy of Sciences.

The discovery of the C60 Buckminsterfullerene, and the related class of molecules the fullerenes, in the mid-1980s earned Professors Harry Kroto, Robert Curl, and the late Richard Smalley the Nobel Prize in Chemistry in 1996.

It has a cage-like spherical structure made up from 20 hexagons and 12 pentagons and resembles a soccer ball, earning it the nickname “buckyball.”

Molecular surgery

In a recent breakthrough in synthetic chemistry, Japanese scientists from Kyoto have invented a molecular surgery technique allowing them to successfully permanently seal small molecules such as H2 and H2O inside C60.

They used a set of surgical synthetic procedures on the C60 “cage” that produced an opening large enough to “push” an H2 or H2O molecule inside at high temperature and pressure. The system was then cooled down to stabilize the entrapped molecule inside and the cage was surgically repaired to reproduce a C60.

Horsewill adds: “This technique succeeds in combining perhaps the universe’s most beautiful molecule C60 with its simplest.”

The Nottingham research group has employed a technique called inelastic neutron scattering (INS) where a beam of neutrons—fundamental particles that make up the atomic nucleus—is used to investigate the “cage rattling” motion of the guest molecules within the C60.

Their investigations have given an insight into the wavelike nature of H20 and H2 molecules and their orbital and rotational motion as they move within the C60.

New types of water

Professor Malcolm Levitt, of the School of Chemistry at the University of Southampton, who has used the technique nuclear magnetic resonance (NMR) to study the quantum properties of the caged molecules, says: “By confining small molecules such as water in fullerene cages we provide the controlled environment of a laboratory but on the scale of about one nanometer.

“Under these conditions, the confined molecules reveal a wave-like nature and behave according to the laws of quantum mechanics. Apart from their intrinsic interest, we expect that the special properties of these materials will lead to a variety of applications, such as new ways to brighten the images of MRI scans, and new types of computer memory.”

The paper also separately identifies two subtly different forms of H2O—ortho-water and para-water. These so called nuclear spin-isomers also owe their separate identities to quantum mechanical principles.

Researchers from Brown University, as well as scientists in Japan, France, Estonia, and the UK contributed to the findings.

Source: University of Nottingham

Pesar moléculas individualmente.

‘Nanobridge’ weighs molecules one by one

• futurity.org
• Marcus Woo-caltech
• August 27th, 2012
• view original

This scanning electron micrograph shows one of the molecule-weighing devices. The bridge-like section at the center vibrates sideways. The scale bar at the bottom is two microns.Photo by: Credit:Scott Kelberg and Michael Roukes/Caltech

Researchers say the new technology will eventually help doctors diagnose diseases, enable biologists to study viruses, probe the molecular machinery of cells, and even allow scientists to better measure nanoparticles and air pollution.

Described in the journal Nature Nanotechnology, the device—which is only a couple millionths of a meter in size—consists of a tiny, vibrating bridge-like structure. When a particle or molecule lands on the bridge, its mass changes the oscillating frequency in a way that reveals how much the particle weighs.

“As each particle comes in, we can measure its mass,” says Michael Roukes, professor of physics, applied physics, and bioengineering at California Institute of Technology (Caltech). “Nobody’s ever done this before.”

The new instrument is based on a technique Roukes and his colleagues developed over the last 12 years. In work published in 2009, they showed that a bridge-like device—called a nanoelectromechanical system (NEMS) resonator—could indeed measure the masses of individual particles, which were sprayed onto the apparatus.

The difficulty, however, was that the measured shifts in frequencies depended not only on the particle’s actual mass, but also on where the particle landed. Without knowing the particle’s landing site, the researchers had to analyze measurements of about 500 identical particles in order to pinpoint its mass.

But with the new and improved technique, the scientists need only one particle to make a measurement. “The critical advance that we’ve made in this current work is that it now allows us to weigh molecules—one by one—as they come in,” Roukes says.

To do so, the researchers analyzed how a particle shifts the bridge’s vibrating frequency. All oscillatory motion is composed of so-called vibrational modes. If the bridge just shook in the first mode, it would sway side to side, with the center of the structure moving the most.

The second vibrational mode is at a higher frequency, in which half of the bridge moves sideways in one direction as the other half goes in the opposite direction, forming an oscillating S-shaped wave that spans the length of the bridge. There is a third mode, a fourth mode, and so on. Whenever the bridge oscillates, its motion can be described as a mixture of these vibrational modes.

The team found that by looking at how the first two modes change frequencies when a particle lands, they could determine the particle’s mass and position, explains Mehmet Selim Hanay, a postdoctoral researcher in Roukes’s lab and first author of the paper.

“With each measurement we can determine the mass of the particle, which wasn’t possible in mechanical structures before.”

Traditionally, molecules are weighed using a method called mass spectroscopy, in which tens of millions of molecules are ionized—so that they attain an electrical charge—and then interact with an electromagnetic field. By analyzing this interaction, scientists can deduce the mass of the molecules.

The problem with this method is that it does not work well for more massive particles—like proteins or viruses—which have a harder time gaining an electrical charge. As a result, their interactions with electromagnetic fields are too weak for the instrument to make sufficiently accurate measurements.

The new device, on the other hand, does work well for large particles. In fact, the researchers say, it can be integrated with existing commercial instruments to expand their capabilities, allowing them to measure a wider range of masses.

The researchers demonstrated how their new tool works by weighing a molecule called immunoglobulin M (IgM), an antibody produced by immune cells in the blood. By weighing each molecule—which can take on different structures with different masses in the body—the researchers were able to count and identify the various types of IgM.

Medical uses

Not only was this the first time a biological molecule was weighed using a nanomechanical device, but the demonstration also served as a direct step toward biomedical applications. Future instruments could be used to monitor a patient’s immune system or even diagnose immunological diseases. For example, a certain ratio of IgM molecules is a signature of a type of cancer called Waldenström macroglobulinemia.

In the more distant future, the new instrument could give biologists a view into the molecular machinery of a cell. Proteins drive nearly all of a cell’s functions, and their specific tasks depend on what sort of molecular structures attach to them—thereby adding more heft to the protein—during a process called posttranslational modification.

By weighing each protein in a cell at various times, biologists would now be able to get a detailed snapshot of what each protein is doing at that particular moment in time.

Another advantage of the new device is that it is made using standard, semiconductor fabrication techniques, making it easy to mass-produce. That’s crucial, since instruments that are efficient enough for doctors or biologists to use will need arrays of hundreds to tens of thousands of these bridges working in parallel.

“With the incorporation of the devices that are made by techniques for large-scale integration, we’re well on our way to creating such instruments,” Roukes says. This new technology, the researchers say, will enable the development of a new generation of mass-spectrometry instruments.

The team includes researchers from the Kavli Nanoscience Institute at Caltech and Commissariat à l’Energie Atomique et aux Energies Alternatives, Laboratoire d’électronique des technologies de l’information (CEA-LETI) in Grenoble, France.

Support was provided by the Kavli Nanoscience Institute, the National Institutes of Health, the National Science Foundation, the Fondation pour la Recherche et l’Enseignement Superieur from the Institut Merieux, the Partnership University Fund of the French Embassy to the USA, an NIH Director’s Pioneer Award, the Agence Nationale pour la Recherche through the Carnot funding scheme, a Chaire d’Excellence from Fondation Nanosciences, and European Union CEA Eurotalent Fellowships.

Source: Caltech

Energía solar más eficiente.

From icy water to steam via nanoparticles

• futurity.org
• Jade Boyd-rice
• November 19th, 2012
• view original

New technology that uses nanoparticles to convert solar energy directly into steam is about "a lot more than electricity," says Naomi Halas of the Laboratory for Nanophotonics at Rice University. "With this technology, we are beginning to think about solar thermal power in a completely different way." (Credit:

The solar steam method has an overall energy efficiency of 24 percent. Photovoltaic solar panels, by comparison, typically have an overall energy efficiency around 15 percent. Inventors of solar steam expect the first uses of the new technology won’t be for electricity generation but rather for sanitation and water purification in developing countries.

“This is about a lot more than electricity,” says Naomi Halas of the Laboratory for Nanophotonics at Rice University. “With this technology, we are beginning to think about solar thermal power in a completely different way.”

Straight from the Source

Read the original study

DOI: 10.1021/nn304948h

As reported in ACS Nano, the efficiency of solar steam is due to the light-capturing nanoparticles that convert sunlight into heat. When submerged in water and exposed to sunlight, the particles heat up so quickly they instantly vaporize water and create steam. Halas says the solar steam’s overall energy efficiency can probably be increased as the technology is refined.

“We’re going from heating water on the macro scale to heating it at the nanoscale,” Halas says. “Our particles are very small—even smaller than a wavelength of light—which means they have an extremely small surface area to dissipate heat. This intense heating allows us to generate steam locally, right at the surface of the particle, and the idea of generating steam locally is really counterintuitive.”

To show just how counterintuitive, Rice graduate student Oara Neumann videotaped a solar steam demonstration in which a test tube of water containing light-activated nanoparticles was submerged into a bath of ice water. Using a lens to concentrate sunlight onto the near-freezing mixture in the tube, Neumann showed she could create steam from nearly frozen water.

Steam is one of the world’s most-used industrial fluids. About 90 percent of electricity is produced from steam, and steam is also used to sterilize medical waste and surgical instruments, to prepare food, and to purify water.

Most industrial steam is produced in large boilers—solar steam’s efficiency could allow it to become economical on a much smaller scale.

People in developing countries will be among the first to see the benefits of solar steam. Rice engineering undergraduates have already created a solar steam-powered autoclave that’s capable of sterilizing medical and dental instruments at clinics that lack electricity. Halas also won a Grand Challenges grant from the Bill and Melinda Gates Foundation to create an ultra-small-scale system for treating human waste in areas without sewer systems or electricity.

“Solar steam is remarkable because of its efficiency,” says Neumann, the lead co-author on the paper. “It does not require acres of mirrors or solar panels. In fact, the footprint can be very small. For example, the light window in our demonstration autoclave was just a few square centimeters.”

Another potential use could be in powering hybrid air-conditioning and heating systems that run off of sunlight during the day and electricity at night. Halas, Neumann, and colleagues have also conducted distillation experiments and found that solar steam is about two-and-a-half times more efficient than existing distillation columns.

Halas, a professor in electrical and computer engineering and of physics, chemistry, and biomedical engineering, specializes in creating and studying light-activated particles. One of her creations, gold nanoshells, is the subject of several clinical trials for cancer treatment.

For the cancer treatment technology and many other applications, Halas’ team chooses particles that interact with just a few wavelengths of light. For the solar steam project, Halas and Neumann set out to design a particle that would interact with the widest possible spectrum of sunlight energy. Their new nanoparticles are activated by both visible sunlight and shorter wavelengths that humans cannot see.

“We’re not changing any of the laws of thermodynamics,” Halas says. “We’re just boiling water in a radically different way.”

The research was supported by the Welch Foundation and the Bill and Melinda Gates Foundation.

Source: Rice University

Utilizar la energía de los cambios de temperatura.

Scientists use nanotechnology to harvest electricity from temperature fluctuations

• engadget.com
• Steve Dent
• November 21st, 2012
• view original

So far your footsteps, breath and nervous energy have all been tapped to charge up batteries, and now researchers from the Georgia Institute of Technology scientists have pulled it off using thermal changes. They did it with so-called pyroelectric nanogenerators, which use polarization changes to harvest heat energy from temperature fluctuations. Normally output current is too low for commercial electronics, but by making one with lead zirconate titanate (PZT), the team was able to create a device that could charge a Li-ion coin battery to power a green LED for a few seconds. The researchers predict that by doubling the surface area, they could drive wireless sensors or LCDs using only environmental temperature changes from an engine or water pipe, for instance. The result could be green power, but without all that pesky moving around.

Teletransportación cuántica entre dos objetos macroscópicos.

Researchers Achieve Quantum Teleportation Between Two Macroscopic Objects For The First Time

• popsci.com
• Clay Dillow
• November 12th, 2012

Quantum Teleportation Explained In case you want to try this at home.

Sometimes it’s tough to get excited about stuff happening in quantum technologies, not because it’s anything less than fascinating but because it can be so hard to wrap your head around this stuff and anyhow the practical applications often seem very far away. But this is one of those milestones that you have to appreciate: Physicists have for the first time teleported quantum information from one macroscopic object to another.

Researchers have been able to teleport quantum information for a while now. Quick quantum primer: This isn’t Star Trek-style teleportation, but the transfer of information--of quantum states--from one place to another without that information crossing the space between them in any way. This is achieved through the strange quantum phenomenon of entanglement, which allows two quantum objects to share the same quantum state such that if you influence one particle you also influence the other, whether they are separated by nanometers or light-years.

So by entangling two photons, for instance, physicists have demonstrated the ability to transmit quantum information from one place to another by encoding it in these quantum states--influence one of the pair and a change can be measured in the other without any information actually passing between the two. Researchers have done this before, between photons, between ions, and even between a macroscopic object and a microscopic object. But now Chinese researchers have, for the first time, achieved quantum teleportation between two macroscopic objects across nearly 500 feet using entangled photons.

That’s pretty huge. The two bundles of rubidium atoms that served as sender and receiver are more or less analogs for what we hope will someday be our “quantum Internet”--a system of routers like the ones we have now that, instead of beaming information around a vast network of fiber optic wires, will send and receive information through entangled photons. So in a way, this is like a first proof of concept, evidence that the idea works at least in the lab.

Now all we have to do is figure out is how to build several of these in series so they can actually pass information from one to the other. To do that, we only have to somehow force these quantum states to exist for longer than the hundred microseconds or so that they last now before degrading. Sounds easy enough.

Breakthrough Nanoparticle Halts Multiple Sclerosis

Northwestern Medicine researchers developed a biodegradable nanoparticle (shown here) that regulates the immune system in mice with multiple sclerosis.

In a breakthrough for nanotechnology and multiple sclerosis, a biodegradable nanoparticle turns out to be the perfect vehicle to stealthily deliver an antigen that tricks the immune system into stopping its attack on myelin and halt a model of relapsing remitting multiple sclerosis (MS) in mice, according to new Northwestern Medicine research.

The new nanotechnology also can be applied to a variety of immune-mediated diseases including, Type 1 diabetes, food allergies, and airway allergies such as asthma. 

In MS, the immune system attacks the myelin membrane that insulates nerves cells in the brain, spinal cord, and optic nerve. When the insulation is destroyed, electrical signals can’t be effectively conducted, resulting in symptoms that range from mild limb numbness to paralysis or blindness. About 80 percent of MS patients are diagnosed with the relapsing remitting form of the disease.

Noticia completa: http://www.feinberg.northwestern.edu/news/2012/11/nanoparticle.html

Nanocrystals Detect Internal Damages of Composite Materials

Picture of zinc oxide tetrapods taken by scanning electron microscope (Copyright 2012, Wiley)

"The luminescent features of zinc oxide tetrapod crystals are well established. According to our work hypothesis, these characteristics showed pronounced variations under a mechanical load, and we realised that it could help to detect internal damages of composite materials", says Dr. Yogendra Mishra of Kiel University's Technical Faculty. In one experiment, the scientists added zinc oxide tetrapod shaped crystals to a silicone (polydimethylsiloxane) polymer and tested its general properties. They found that the resulting composite material is on the one hand stronger than silicon and on the other hand emits light in different colors when exposed to UV light. When the material is subjected to mechanical stress, the intensities of the emitted lights changes.

Fuente: http://www.azonano.com/news.aspx?newsID=26077

Researchers Use Gold Nanoparticles for Low-Cost Semiconductors Production

A completely new method of manufacturing the smallest structures in electronics could make their manufacture thousands of times quicker, allowing for cheaper semiconductors. The findings have been published in the latest issue of Nature.

A completely new method of manufacturing the smallest structures in electronics could make their manufacture thousands of times quicker, allowing for cheaper semiconductors. (Credit: Lund University, Sweden)

Instead of starting from a silicon wafer or other substrate, as is usual today, researchers have made it possible for the structures to grow from freely suspended nanoparticles of gold in a flowing gas.
Behind the discovery is Lars Samuelson, Professor of Semiconductor Physics at Lund University, Sweden, and head of the University's Nanometre Structure Consortium. He believes the technology will be ready for commercialisation in two to four years' time. A prototype for solar cells is expected to be completed in two years.
"When I first suggested the idea of getting rid of the substrate, people around me said 'you're out of your mind, Lars; that would never work'. When we tested the principle in one of our converted ovens at 400°C, the results were better than we could have dreamt of", he says.
"The basic idea was to let nanoparticles of gold serve as a substrate from which the semiconductors grow. This means that the accepted concepts really were turned upside down!"
Since then, the technology has been refined, patents have been obtained and further studies have been conducted. In the article in Nature, the researchers show how the growth can be controlled using temperature, time and the size of the gold nanoparticles.
Recently, they have also built a prototype machine with a specially built oven. Using a series of ovens, the researchers expect to be able to 'bake' the nanowires, as the structures are called, and thereby develop multiple variants, such as p-n diodes.
A further advantage of the technology is avoiding the cost of expensive semiconductor wafers.
"In addition, the process is not only extremely quick, it is also continuous. Traditional manufacture of substrates is batch-based and is therefore much more time-consuming", adds Lars Samuelson.
At the moment, the researchers are working to develop a good method to capture the nanowires and make them self-assemble in an ordered manner on a specific surface. This could be glass, steel or another material suited to the purpose.
The reason why no one has tested this method before, in the view of Professor Samuelson, is that today's method is so basic and obvious. Such things tend to be difficult to question.
However, the Lund researchers have a head start thanks to their parallel research based on an innovative method in the manufacture of nanowires on semiconductor wafers, known as epitaxy – consequently, the researchers have chosen to call the new method aerotaxy. Instead of sculpting structures out of silicon or another semiconductor material, the structures are instead allowed to develop, atomic layer by atomic layer, through controlled self-organisation.
The structures are referred to as nanowires or nanorods. The breakthrough for these semiconductor structures came in 2002 and research on them is primarily carried out at Lund, Berkeley and Harvard universities. The Lund researchers specialise in developing the physical and electrical properties of the wires, which helps create better and more energy-saving solar cells, LEDs, batteries and other electrical equipment that is now an integrated part of our lives.
Source: http://www.lu.se

Tosquedad en capas superficiales de celdas solares nanoestructuradas

superficie de la célula solar Policristalino-Si.

 Rango los 90ìm los x 90ìm de la Exploración con un AFM

Una tecnología de buen aprovechamiento y que reduce costes son las finas películas de silicio policristalino. Se necesitan propiedades eléctricas y cristalinas muy buenas de las capas para alcanzar eficiencias de conversión de energía altamente competitivas. Y aun que en esta tecnología su bajo costo juega un papel fundamental, los substratos son generalmente muy ásperos y por tanto no transparentes lo que presenta una desventaja para la celda solar. Dicha tosquedad del substrato tiene un efecto grande sobre todos los aspectos de el proceso del PC-Si; se necesitan sustratos más lisos que proporcionen una mayor capa amortiguadora y un aumento en el voltaje así como en la eficiencia de la celda solar. Dicha eficiencia se obtendría si la celda solar de silicio amorfas hidrogenadas pudieran ser mejoradas para aumentar la absorción luminosa en las capas delegadas introduciéndole un dispersor de luz en la superficie áspera.

Célula solar que consiste en una sola molécula

DOMINGO, SEPTIEMBRE 30, 2012

A continuacion presentare una noticia, la cual como su titulo lo dice explica como un grupo de investigadores lograron comprender las propiedades fotosinteticas. El uso de proteinas favorecerá el camino hacia los generadores de corriente.

Célula solar que consiste en una sola molécula

"Un equipo de científicos de la Universidad Técnica de Munich y Universidad de Tel Aviv desarrollaron un método para medir las fotocorrientes de un único sistema funcionalizado de proteínas fotosintéticas. Los científicos pudieron demostrar que dicho sistema se puede integrar y dirigir de forma selectiva en arquitecturas de dispositivos fotovoltaicos artificiales mientras conserva sus propiedades funcionales biomoleculares. Las proteínas actúan como bombas de electrones de una sola molécula inducidas por la luz y altamente eficientes, capaces de actuar como generadores de corriente en los circuitos eléctricos a escala nanométrica.

El equipo interdisciplinario publicó los resultados en la revista Nature Nanotechnology, bajo el título "Photocurrent of a single photosynthetic protein" (fotocorriente de una proteína fotosintética individual).

Los científicos investigaron el centro de reacción del fotosistema-I que es un complejo de proteína de clorofila localizado en las membranas de los cloroplastos de las cianobacterias. Las plantas, las algas y las bacterias utilizan la fotosíntesis para convertir la energía solar en energía química. Las etapas iniciales de este proceso -en las que se absorbe la luz y se transfieren la energía y los electrones- están mediadas por proteínas fotosintéticas compuestas de complejos de carotenoides y clorofila. Hasta ahora, ninguno de los métodos disponibles eran lo suficientemente sensibles como para medir las fotocorrientes generadas por una sola proteína El fotosistema-I exhibe excelentes propiedades optoelectrónicas que sólo se encuentran en los sistemas fotosintéticos. La dimensión de la nanoescala, además, hace del fotosistema-I una unidad prometedora para las aplicaciones en la optoelectrónica molecular."

Al hablar de celdas solares o el cambio de energia solar hacia energia química hablamos de procesos demasiado complejos, ultimamente los descubrimientos en generadores químicos a sido de alta importancia, como pudimos ver en la noticia; es necesario entender que no solo aportaran informacion y apoyo a los paneles solares tambien ayudaran en la industria de la optica.

Fuente: http://www.nanowerk.com/news2/newsid=26855.php

Agenda Ciudadana de Ciencia, Tecnología e Innovación. VOTEN!

 

Generar Vapor con el Sol activado por Nanoparticulas

La conversión de luz a calor por nanoparticulas conductivas, bajo iluminación laser, a demostrado que induce dramáticamente localizado el calentamiento e incluso evaporación de su medio anfitrión (liquido en que están depositadas). En este proceso podemos usar la energía solar como base para la evaporación de un gas, sin la necesidad de tener que calentar previamente el liquido al punto de ebullición pues las partículas submicrometricas absorben la luz en el espectro de la luz solar y se dispersan y calientan el agua por en sima de los 100°C en geometrías compactas. En este caso las partículas metálicas conocidas como plasmones superficiales son las responsables absorbedoras intensas de radiación óptica, debido a las oscilaciones colectivas de su electrón de conducción deslocalizado. Estas partículas cuando se excitan por  resonancia, la energía no vuelve a irradiar a través de la dispersión de luz si no que se disipa a través de una amortiguación Landau (no radiactiva) que resulta en el incremento dramático de la temperatura en la proximidad de la nanopartiícula. Es de gran interés en aplicaciones de medicina como en la  terapia de cáncer fototermica.

 
La tecnología ahi la encontramos, ahora solo hay q aprovecharla y darle un uso