Microstructuring of glass by laser irradiation: applications on microoptics and microfluidics

En la presente tesis se propone la fabricación de elementos en vidrio para micro-óptica y microfluídica que exigen microestructuras de alta calidad. Estos elementos son altamente demandados desde sectores industriales, por lo que se precisan técnicas de procesado, rápidas, sencillas y de bajo coste

Laser-Based Fabrication for Microfluidics Devices on Glass for Medical Applications

We report a laser-based process for microstructuring glass materials for microfluidics applications. The hybrid technique is composed of a nanosecond Q-Switch Nd:YVO4 laser for fabricating the initial microfluidic microstructures on soda-lime glass substrates and a thermal treatment for reshaping and improving its morphological and optical qualities. The proposed technique preserves the advantages of the laser direct-write technique in terms of design flexibility, simplicity, fast prototyping, low cost, and so on. The beam spot size, pulse overlapping, ablation threshold, debris deposition, heating temperature, and time are investigated and optimized for fabricating optimal microfluidics structures on glass. The manufactured chips for circulating tumor cells (CTCs) capture were tested with tumor cells (Hec 1A) after being functionalized with an EpCAM antibody coating. Cells were successfully arrested on the pillars after being flown through the device giving our technology a translational application in the field of cancer research

Bacterias diazotroficas y solubilizadoras de fósforo aisladas de las especies forestles altoandinas colombianas Weinmannia tomentosa y Escallonia myrtilloides

Encenillo (Weinmannia tomentosa Lf) and pagoda (Escallonia myrtilloides Lf) are dominant native tree species that can be found in the forests of the complex Andean Guerrero (Cundinamarca, Colombia). Forty two phosphorus-solubilizing bacteria and 125 nitrogen-fixing strains were isolated from the rhizosphere of these trees, out of which the microbial strains presenting the best five results of dissolution of phosphate and acetylene reduction by plant species were selected. The diazotrophic strains selected were identified as close to Enterobacter gergoviae, Alcaligenes sp. (E13C and E12E strains), Enterobacter sp. (E14C.2 strain), Pseudomonas sp., Sphingomonas sp., Paenibacillus sp., Achromobacter sp., Flavobacterium adoratum, and Klebsiella pneumoniae, and as phosphate-solubilizingbacteria near to Pantoea agglomerans, Pantoea sp., Brevudimonas sp., Enterobacter sp. (E6C.1 strain), Burkholderia cepacia, Arthrobacter sp., Aeromicrobium sp., Corynebacterium sp., Pimelobacter sp. and Micrococcus sp. In order to perform preliminary in vivo tests with the chosen microorganisms, it was inoculated bacterial mixture to encenillo and pagoda seedlings and evaluated their longitudinal growth for three months under greenhouse conditions. The major averages were obtained with the inoculation of Enterobacter gergoviae and Pantoea sp. in encenillo seedlings (average increase of 51% and 57% greater than the controls without microbial inoculation and sterile molasses medium, respectively) and the mixture of all selected bacteria in pagoda (Stimulation of 16% and 32% compared to controls molasses and without bacterial inoculation, respectively). The results showed that all the combinations using microbial inocula significantly stimulated longitudinal growth (Duncan multiple range test P<0.05). The synergism shown by co-inoculation of diazotrophic bacteria and phosphate solubilizing bacteria indicate the potential of these microorganisms as plant growth promoters and biofertilizers.El encenillo (Weinmannia tomentosa L.f) y la pagoda (Escallonia myrtilloides L.f) son especies forestales nativas predominantes en bosques altoandinos del complejo Guerrero (Cundinamarca, Colombia). De la rizosfera de estos árboles se aislaron 42 bacterias solubilizadoras de fósforo y 125 fijadoras de nitrógeno, de las cuales se escogieron las cepas microbianas que presentaron los cinco mejores resultados de disolución de fosfato y reducción de acetileno por cada especie vegetal. Las cepas diazotróficas escogidas se identificaron como cercanas a Enterobacter gergoviae, Alcaligenes sp. (Cepas E12E y E13C), Enterobacter sp (cepa E14C.2), Pseudomonas sp., Sphingomonas sp., Paenibacillus sp., Achromobacter sp., Flavobacterium adoratum y Klebsiella pneumoniae; y como solubilizadoras de fósforo a Pantoea agglomerans, Pantoea sp., Brevudimonas sp., Enterobacter sp. (Cepa E6C.1), Burkholderia cepacia, Arthrobacter sp., Aeromicrobium sp., Corynebacterium sp., Pimelobacter sp. y Micrococcus sp. Se realizaron ensayos preliminares in vivo con los microorganismos escogidos y se inocularon diferentes combinaciones bacterianas en plántulas de encenillo y pagoda. Se evaluó el crecimiento longitudinal durante tres meses bajo condiciones de invernadero. Los mayores promedios se obtuvieron con la inoculación de Enterobacter gergoviae y Pantoea sp., en plántulas de encenillo (incremento promedio de 51% y 57% más que los controles sin ninguna inoculación microbiana y medio melaza estéril, respectivamente) y con la mezcla de todas las bacterias escogidas en pagoda (estimulación de 16% y 32%, con respecto a los controles melaza y sin inoculación bacteriana, respectivamente). Todas las combinaciones microbianas utilizadas estimularon significativamente el crecimiento longitudinal (prueba de Duncan P<0,05). El sinergismo mostrado por la co-inoculación de bacterias diazotróficas y solubilizadoras de fósforo indican el potencial de estos microorganismos como promotores de crecimiento vegetal y posibles biofertilizantes

Laser-based surface multistructuring using optical elements and the Talbot effect

We present a laser based technique combined with the Talbot effect for microstructuring surfaces. The use of the Talbot effect is introduced as a solution to avoid damage of the periodic object used for micropattering different surfaces during the ablation process. The fabrication of two periodic objects (a mask and a microlens array) for micropattering surfaces and the identification of their Talbot planes is presented. A metal foil is ablated at distances corresponding to selected Talbot planes of the periodic objects. The setup allows us to design the desired pattern and the result is a multistructured surface with a high number of identical microholes, achieving a minimum diameter around 4μm. The different aspect of the periodic object working in direct contact and working at these Talbot distances is shown. These pictures reveal the advantages of working of using Talbot effect for a rapid, repeatable and no-contaminant multistructuring. Some industrial applications are illustrated.This work has been supported by the Consellería de Cultura, Xunta de Galicia/FEDER, Spain under Contract EM2012/019S

Product Design by Additive Manufacturing for Water Environments: Study of Degradation and Absorption Behavior of PLA and PETG

Additive manufacturing technologies are shifting from rapid prototyping technologies to end use or final parts production. Polymeric material extrusion processes have been broadly addressed with a specific definition of all parameters and variables for all different of technologies approaches and materials. Recycled polymeric materials have been studied due to the growing importance of the environmental awareness of the contemporary society. Beside this, little specific research has been found in product development applications for AM where the printed parts are in highly moisture environments or surrounded by water, but polymers have been for long used in such industries with conventional manufacturing approaches. This work focuses on the analysis and comparison of two different additively manufactured polymers printed by fused filament fabrication (FFF) processes using desktop-size printers to be applied for product design. The polymers used have been a recycled material: polyethylene terephthalate glycol (PETG) and polylactic acid (PLA). Degradation and water absorption behaviors of both materials are presented, analyzed and discussed in this paper, where different samples have been immersed in saturated solutions of water with maritime salt and sugar together with a control sample immersed in distilled water. The samples have been dimensionally and weight-controlled weekly as well as microscopically analyzed to understand degradation and absorption processes that appear in the fully saturated solutions. The results revealed how the absorption process is stabilized after a reduced number of weeks for both materials and how the degradation process is more remarked in the PLA material due to its organic nature

Laser Surface Microstructuring of Biocompatible Materials Using a Microlens Array and the Talbot Effect: Evaluation of the Cell Adhesion

A laser based technique for microstructuring titanium and tantalum substrates using the Talbot effect and an array of microlenses is presented. By using this hybrid technique; we are able to generate different patterns and geometries on the top surfaces of the biomaterials. The Talbot effect allows us to rapidly make microstructuring, solving the common problems of using microlenses for multipatterning; where the material expelled during the ablation of biomaterials damages the microlens. The Talbot effect permits us to increase the working distance and reduce the period of the patterns. We also demonstrate that the geometries and patterns act as anchor points for cells; affecting the cell adhesion to the metallic substrates and guiding how they spread over the materialThis work has been supported under contracts MAT2015-71119-R, Ministerio de Economía y Competitividad, and ISCIII/PI14-01140/FEDER, Instituto de Salud Carlos III, Spain. M. Aymerich acknowledges a Pre-Doctoral Fellowship from Xunta de Galicia (Spain) financed by the Secretaría Xeral de Universidades and the Fondo Social Europeo (FSE). D. Nieto thanks the Consellería de Cultura, Spain for their support under the Galician Programme for Research Innovation and Growth (2011–2015) (I2C Plan)S

MoS2-Carbon Nanodots as a New Electrochemiluminescence Platform for Breast Cancer Biomarker Detection

In this work, we present the combination of two different types of nanomaterials, 2D molybdenum disulfide nanosheets (MoS2-NS) and zero-dimensional carbon nanodots (CDs), for the development of a new electrochemiluminescence (ECL) platform for the early detection and quantification of the biomarker human epidermal growth factor receptor 2 (HER2), whose overexpression is associated with breast cancer. MoS2-NS are used as an immobilization platform for the thiolated aptamer, which can recognize the HER2 epitope peptide with high affinity, and CDs act as coreactants of the anodic oxidation of the luminophore [Ru(bpy)3]2+. The HER2 biomarker is detected by changes in the ECL signal of the [Ru(bpy)3]2+/CD system, with a low detection limit of 1.84 fg/mL and a wide linear range. The proposed method has been successfully applied to detect the HER2 biomarker in human serum samplesThis work has been financially supported by the Spanish Ministry of Economy and Competitiveness (PID2020-116728RB-I00, PID2020-116661RB-I00, CTQ2015-71955-REDT (ELECTROBIONET)), Community of Madrid (TRANSNANOAVANSENS, S2018/NMT-4349, and FotoArt (P2018/NMT4367), project S2018/NMT-4291 TEC2SPACE), MINECO (project CSIC13-4E-1794) and EU (FEDER, FSE). IMDEA Nanociencia receives support from the “Severo Ochoa” Programme for Centres of Excellence in R&D (MINECO, Grant CEX2020-001039-S)

Análisis de los sistemas actuales en oftalmología para el estudio de enfermedades relacionadas con la modificación geométrica de la arquitectura corneal

[ES] El análisis de la morfología corneal es un procedimiento muy útil en el diagnóstico clínico de determinadas patologías oculares, especialmente las relacionadas con alteraciones ectásicas corneales. Desde la aparición de los sistemas basados en Discos de Plácido a los sistemas que incorporan la fotografía Scheimpflug, existe una variedad de instrumentos que ofrecen la posibilidad de analizar con gran precisión parámetros de la morfología corneal. En esta comunicación se revisan los diversos instrumentos que han sido utilizados para caracterizar la morfología corneal, estando todos influenciados, en mayor o menor medida, por factores como la rapidez de adquisición de datos y la estabilidad de la película lagrimal. [ENG] The analysis of the corneal shape is a very useful process that permits the clinical diagnosis of determined ocular pathologies, especially those related with corneal ectatic disorders. From the appearance of the systems based on the Placido-disc technology to the new systems that combine the accurate Scheimpflug photography, there are a variety of ophthalmic instruments that permit to analyze with high accuracy some parameters of the corneal shape. This communication reviews the different systems that have been used to characterize the corneal morphology, being all of them influenced, to a greater or lesser extent, by factors such as the speed for data acquisition and the stability of the tear film.Centro Universitario de la Defensa. Escuela de Turismo de Cartagena. Escuela Técnica Superior de Ingeniería Industrial UPCT. Escuela Técnica Superior de Ingeniería de Telecomunicación (ETSIT). Escuela de Ingeniería de Caminos y Minas (EICM). Escuela de Arquitectura e Ingeniería de Edificación (ARQ&IDE). Parque Tecnológico de Fuente Álamo. Navantia. Campus Mare Nostrum. Estación Experimental Agroalimentaria Tomás Ferr