Una revolució en petit. Mig segle de Nanotecnologia

Mini-revolution: Half a Century of Nanotechnology.Nanoscience has progressed over the last 50 years from a scattered set of basic but outstanding breakthroughs to hundreds of research groups world-wide, continuously announcing the discovery of novel nanomaterials and fascinating nanodevices. Nanotechnology is becoming real; in fact,many of these advances have become part of our daily life. This article describes the basic features characterizing current research in nanotechnology and its main application sectors. In addition, this study also covers other issues like funding or public perception of this multidisciplinary fiel

La Nanotecnología, una revolución desconocida

La nanotecnología, gracias a la explotación de su carácter multidisciplinar, de su capacidad para sintonizar las propiedades de la materia a través de los denominados efectos de tamaño, y de la adecuada combinación de diversas técnicas de fabricación, proporciona nuevos productos y aplicaciones en prácticamente todos los sectores económicos. Esta versatilidad ha hecho que la nanotecnología sea destino de inmensas inversiones que están dando lugar a un mercado emergente. En paralelo con este desarrollo, se han puesto de manifiesto ciertas inquietudes relacionadas con los posibles riesgos de la nanotecnología. La respuesta de la mayor parte de los países ha sido similar, poniendo en marcha programas para evaluar el impacto de la nanotecnología, estableciendo las normativas adecuadas, y mejorando los procesos de comunicación con la sociedad. En el caso de España, la respuesta ha sido diferente, ya que no se han diseñado iniciativas para involucrar a la población en el debate de las nanotecnología

Identification of water content in nanocavities

A tapered dielectric waveguide that scans, at constant height, a sample containing a viral capsid is studied by combining a lattice gas model to simulate water meniscus formation and a finite difference time domain algorithm for light propagation through the media involved. Our results show different contrasts related to different water contents and different meniscus orientations. We propose this method as a way to study water content and evaporation process in nanocavities being either biological, like viral capsides, or nonbiological, like photonic crystalsThis work has been funded through projects FIS2009-13403-C02-01 (MINECO), S2009-MAT-1467 (CAM), and CSD2010-00024 (MINECO

Nanotecnología: la revolución de lo diminuto

Este artículo repasa el camino recorrido por la nanotecnología desde los laboratorios a las fábricas y de estas a los supermercados, indicando también parte del que queda por transitar para que esta revolución de lo diminuto se consolide

Icosahedral Ni nanowires formed from nanocontacts breaking: Identification and characterization by Molecular Dynamics

We present and discuss an algorithm to identify and characterize the long icosahedral structures (staggered pentagonal nanowires with 1-5-1-5 atomic structure) that appear in Molecular Dynamics simulations of metallic nanowires of different species subjected to stretching. The use of this algorithm allows the identification of pentagonal rings forming the icosahedral structure as well as the determination of its number np , and the maximum length of the pentagonal nanowire Lpm. The algorithm is tested with some ideal structures to show its ability to discriminate between pentagonal rings and other ring structures. We applied the algorithm to Ni nanowires with temperatures ranging between 4K and 865K, stretched along the [111], [100] and [110] directions. We studied statistically the formation of pentagonal nanowires obtaining the distributions of length Lpm and number of rings np as function of the temperature. The Lpm distribution presents a peaked shape, with peaks located at fixed distances whose separation corresponds to the distance between two consecutive pentagonal rings

Circular dichroism in magneto-optical forces

In this article we use an exact method to resolve the fields scattered by a spherical magneto-optical particle and calculate the optical forces exerted on it. The resulting force and the contributing components, i.e. magneto-optical gradient force and magneto-optical extinction force, are presented in an analytical form. We also derive analytical expressions for the scattering and extinction cross sections of a magneto-optical particle, expressions which intuitively demonstrate the effect of circular dichroism in magneto-optical scattering and forces. Finally, we demonstrate that the magneto-optical extinction force is the result of circular dichroism in magneto-optical scattering. We show that it is possible to completely cancel the scattering in the forward or in the backward direction, when the incident field is composed of a circularly-polarized reflected beam. Moreover, the directional scattering is interrelated to the direction of the force exerted on the particleComunidad de Madrid (SI1/PJI/2019-00052); Ministerio de Ciencia e Innovación (CEX2018-000805-M, PGC2018-095777-B-C21, PGC2018-095777-B-C22, PID2019-109905GA-C22

Mechanical properties of systems with biological interest: The human Immunoglobulin G

Póster presentado en el Congreso Fuerzas y Tunel, celebrado en San Lorenzo de El Escorial del 12 al 14 de septiembre de 2012.The antibodies are the first line of differentiated defense mechanism of our body. A better understanding of the mechanical properties of such structures would allow us to use this information as an extremely accurate diagnostic tool. The method we rely on to obtain such detailed information is the multi-frequency atomic force microscopy (AFM)[1]. The AFM has several features that are attractive to the biologists. First, it is a tool with molecular resolution that enables imaging in physiologic-like environments[2] and secondly it also provides nano-mechanical and chemical information at time scale relevant for bio-molecular interactions. Dynamic AFM imagesof biological molecules on ambient conditions (liquid) are controlled by nonlinear tip-sample interaction, the cantilever dynamics and the feedback control. In order to extract accurate information about topography and materials properties, these effects have to be taken into account simultaneously. Here we report how to improve the theoretical description of each of these aspects and integrate them into a multi-scale framework that incorporates different levels of computer modeling in order to address the ultimate spacial resolution and force sensitivity of the AFM on biological molecules.Peer Reviewe